Paraoxonase-1 status in patients with hereditary hemochromatosis

PubMed Central

Martinelli, Nicola; García-Heredia, Anabel; Roca, Helena; Aranda, Núria; Arija, Victoria; Mackness, Bharti; Mackness, Michael; Busti, Fabiana; Aragonès, Gerard; Pedro-Botet, Juan; Pedica, Federica; Cataldo, Ivana; Marsillach, Judit; Joven, Jorge; Girelli, Domenico; Camps, Jordi

2013-01-01

Hereditary hemochromatosis (HH) is characterized by accumulation of iron, oxidative stress, inflammation, and fibrogenesis in liver tissue. In this setting, research on the protection afforded by intracellular antioxidants is of clinical relevance. Paraoxonase-1 (PON1) is an enzyme that degrades lipid peroxides. This study investigates the alterations in serum PON1 status, PON1 gene polymorphisms, and PON1 hepatic expression in patients with HH. We performed a case-control study in 77 patients with HH (80.5% men, 22–70 years of age) and 408 healthy individuals (43.1% men, 26–74 years of age). Serum PON1 activities against different substrates and PON1192 and PON155 polymorphisms were analyzed. PON1 protein expression was investigated in 20 liver biopsies. HH patients had significantly lower serum PON1 activity, which was inversely correlated with ferritin (marker of iron stores) and serum 8-isoprostane concentrations (index of oxidative stress). PON1 protein expression in liver tissue was higher in patients and showed stronger staining in hepatocytes surrounding the areas of inflammation. Our study provides preliminary evidence that PON1 may play a role in protecting against iron-induced oxidative stress in hereditary hemochromatosis. PMID:23471031

PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellison, Corie A., E-mail: cellison@buffalo.edu; Crane, Alice L., E-mail: alcrane@buffalo.edu; Bonner, Matthew R., E-mail: mrbonner@buffalo.edu

Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n = 120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase)more » and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P ≤ 0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P ≤ 0.05) and PON1 192 (P ≤ 0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal. -- Highlights: ► CPF exposure resulted in an increase in TCPy and decreases in BuChE and AChE. ► CPOase activity decreased in subjects with the PON1 55LM and PON1 55 MM genotypes. ► Neither PON1 genotype nor CPOase activity had an effect on BuChE or AChE inhibition.« less

Expression and purification of biologically active recombinant human paraoxonase 1 from inclusion bodies of Escherichia coli.

PubMed

Bajaj, Priyanka; Tripathy, Rajan K; Aggarwal, Geetika; Pande, Abhay H

2015-11-01

Human PON1 (h-PON1) is a Ca(2+)-dependent serum enzyme and can hydrolyze (and inactivate) a wide range of substrates. It is a multifaceted enzyme and exhibit anti-inflammatory, anti-oxidative, anti-atherogenic, anti-diabetic, anti-microbial, and organophosphate (OP)-detoxifying properties. Thus, h-PON1 is a strong candidate for the development of therapeutic intervention against these conditions in humans. Insufficient hydrolyzing activity of native h-PON1 against desirable substrate affirms the urgent need to develop improved variant(s) of h-PON1 having enhanced activity. Production of recombinant h-PON1 (rh-PON1) using an Escherichia coli expression system is a key to develop such variant(s). However, generation of rh-PON1 using E. coli expression system has been elusive until now because of the aggregation of over-expressed rh-PON1 protein in inactive form as inclusion bodies (IBs) in the bacterial cells. In this study, we have over-expressed rh-PON1(wt) and rh-PON1(H115W;R192K) proteins as IBs in E. coli, and refolded the inactive enzymes present in the IBs to their active form using in vitro refolding. The active enzymes were isolated from the refolding mixture by ion-exchange chromatography. The catalytic properties of the refolded enzymes were similar to their soluble counterparts. Our results show that the pure and the active variant of rh-PON1 enzyme having enhanced hydrolyzing activity can be produced in large quantities using E. coli expression system. This method can be used for the industrial scale production of rh-PON1 enzymes and will aid in developing h-PON1 as a therapeutic candidate. Copyright © 2015 Elsevier Inc. All rights reserved.

A homogeneous cell-based assay for measurement of endogenous paraoxonase 1 activity.

PubMed

Ahmad, Syed; Carter, Jade J; Scott, John E

2010-05-01

Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that plays an important role in organophosphate detoxification and prevention of atherosclerosis. Thus, there is significant interest in identifying nutritional and pharmacological enhancers of PON1 activity. To identify such compounds, we developed a rapid homogeneous assay to detect endogenous cell-associated PON1 activity. PON1 activity was measured by the simple addition of fluorigenic PON1 substrate DEPFMU to live Huh7 cells in medium and monitoring change in fluorescence. A specific PON1 inhibitor, 2-hydroxyquinoline, was used to confirm that the observed activity was due to PON1. The assay was optimized and characterized with regard to time course, substrate and sodium chloride concentration, number of cells, and tolerance to dimethyl sulfoxide and serum. Aspirin, quercetin, and simvastatin are compounds reported to increase PON1 expression. Consistent with the literature and Western blot data, these compounds enhanced PON1 activity in this assay with comparable efficacies and potencies. A known toxic compound did not increase assay signal. This assay method also detected PON1 activity in normal hepatocytes. Thus, a novel homogeneous assay for detection of endogenous PON1 expression has been developed and is amenable to high-throughput screening for the identification of small molecules that enhance PON1 expression. 2010 Elsevier Inc. All rights reserved.

Repeated Gestational Exposure of Mice to Chlorpyrifos Oxon Is Associated with Paraoxonase 1 (PON1) Modulated Effects in Maternal and Fetal Tissues

PubMed Central

Co, Aila L.; Hay, Ariel M.; MacDonald, James W.; Bammler, Theo K.; Farin, Federico M.; Costa, Lucio G.; Furlong, Clement E.

2014-01-01

Chlorpyrifos oxon (CPO), the toxic metabolite of the organophosphorus (OP) insecticide chlorpyrifos, causes developmental neurotoxicity in humans and rodents. CPO is hydrolyzed by paraoxonase-1 (PON1), with protection determined by PON1 levels and the human Q192R polymorphism. To examine how the Q192R polymorphism influences fetal toxicity associated with gestational CPO exposure, we measured enzyme inhibition and fetal-brain gene expression in wild-type (PON1+/+), PON1-knockout (PON1−/−), and tgHuPON1R192 and tgHuPON1Q192 transgenic mice. Pregnant mice exposed dermally to 0, 0.50, 0.75, or 0.85 mg/kg/d CPO from gestational day (GD) 6 through 17 were sacrificed on GD18. Biomarkers of CPO exposure inhibited in maternal tissues included brain acetylcholinesterase (AChE), red blood cell acylpeptide hydrolase (APH), and plasma butyrylcholinesterase (BChE) and carboxylesterase (CES). Fetal plasma BChE was inhibited in PON1−/− and tgHuPON1Q192, but not PON1+/+ or tgHuPON1R192 mice. Fetal brain AChE and plasma CES were inhibited in PON1−/− mice, but not in other genotypes. Weighted gene co-expression network analysis identified five gene modules based on clustering of the correlations among their fetal-brain expression values, allowing for correlation of module membership with the phenotypic data on enzyme inhibition. One module that correlated highly with maternal brain AChE activity had a large representation of homeobox genes. Gene set enrichment analysis revealed multiple gene sets affected by gestational CPO exposure in tgHuPON1Q192 but not tgHuPON1R192 mice, including gene sets involved in protein export, lipid metabolism, and neurotransmission. These data indicate that maternal PON1 status modulates the effects of repeated gestational CPO exposure on fetal-brain gene expression and on inhibition of both maternal and fetal biomarker enzymes. PMID:25070982

Human paraoxonase 2

PubMed Central

Porntadavity, Sureerut; Permpongpaiboon, Thinnakorn; Sukketsiri, Wanida

2010-01-01

Human paraoxonase 2 (PON2), which is a member of the paraoxonase family, possesses unique properties that distinguish it from PON1 and PON3. PON2 is ubiquitously expressed in many different tissue types and is highly expressed in the vital organs, such as the heart and lungs. Early research revealed that PON2 is exclusively intracellularly found, wherein it functions as an anti-oxidative protein by reducing intracellular and local oxidative stress. Studies in the last five years have demonstrated that PON2 protects against atherosclerosis by preventing low-density lipoprotein (LDL) oxidation, reversing the oxidation of mildly oxidised LDL, inhibiting monocyte chemotaxis, and increasing cholesterol efflux. Recently, emerging evidence has proposed that PON2 is an anti-atherosclerotic and may be associated with cardiovascular disease (CVD). The number of investigations concerning the relationship between two common PON2 polymorphisms and CVD among different ethnic groups and regions is rapidly growing. Here, we briefly review the developments in PON2 research by focusing on past and recent findings. PMID:29255397

Paraoxonase 1 (PON1)-L55M among common variants in the coding region of the paraoxonase gene family may contribute to the glycemic control in type 2 diabetes.

PubMed

Mahrooz, Abdolkarim; Hashemi-Soteh, Mohammad Bagher; Heydari, Masoud; Boorank, Ruzbeh; Ramazani, Fatemeh; Mahmoudi, Ali; Kianmehr, Anvarsadat; Alizadeh, Ahad

2018-05-19

Genome studies have shown that the genes encoding paraoxonase 1 (PON1) and PON2 are associated with glucose metabolism. The goal of this study was to simultaneously evaluate the association between functional variants in PON1 and PON2 genes and susceptibility for type 2 diabetes (T2D) and determine whether they can affect glycemic control. We performed a case-control study with 145 newly diagnosed patients with T2D and 148 controls. The common variants including PON1-Q192R, PON1-L55M and PON2-S311C were genotyped by PCR-based RFLP. A mismatch-PCR/RFLP was applied for genotyping the PON2-A148G variant. The variant PON1-Q192R in males (OR = 2.55, 95%CI 1.16-5.69, p = 0.023) and PON2-A148G in females (OR = 1.56, 95%CI 1.00-2.44, p = 0.059) were associated with T2D. Compared with the LL genotypes of PON1-L55M, HbA1c levels were significantly lower in the LM genotypes (p = 0.01) and MM genotypes (p = 0.032) in patients. Multiple linear regression analyses showed that among the study variants only the PON1-L55M variant as an independent variable significantly associated with glycemic control. This variant significantly influenced glycemic control in patients with poor glycemic control so that it was better with the following order: LL < LM < MM. Based on gamma correlation, there was a significant inverse association between the number of M alleles of the PON1-L55M and HbA1c levels (r = -0.261, p = 0.001). Sex should be considered a confounding variable in association studies on the variants PON1-Q192R and PON2-A148G in T2D. Patients sharing the 55 M allele were prone to having good glycemic control. Our findings provide genetic evidence that the PON1-L55M variant may be a factor contributing to glycemic control. Copyright © 2018 Elsevier B.V. All rights reserved.

Functional paraoxonase 1 variants modify the risk of Parkinson's disease due to organophosphate exposure.

PubMed

Lee, Pei-Chen; Rhodes, Shannon L; Sinsheimer, Janet S; Bronstein, Jeff; Ritz, Beate

2013-06-01

We previously demonstrated that carriers of the "slower metabolizer" MM genotype of paraoxonase (PON1) who were also exposed to ambient organophosphate (OP) pesticides at their residences were at increased risk of developing Parkinson's disease (PD). Here, with a larger sample size, we extend our previous investigation to consider additional sources of ambient exposure and examined two additional functional PON1 variants. From 2001 to 2011, we enrolled incident cases of idiopathic PD and population controls living in central California. We genotyped three well-known functional PON1 SNPs: two exonic polymorphisms (PON1L55M and PON1Q192R) and the promoter region variant (PON1C-108T). Ambient exposures to diazinon, chlorpyrifos, and parathion at residential and workplace addresses were assessed using a validated geographic information system-based model incorporating records of agricultural pesticide applications in California. The odds ratio (OR) for Caucasians exposed to OPs at either residential or workplace addresses varied by PON1 genotype; for exposed carriers of the "faster" metabolizer genotypes, ML or LL, we estimated lower odds ratios (range, 1.20-1.39) than for exposed carriers of the "slower" metabolizer genotype MM (range, 1.78-2.45) relative to unexposed carriers of the faster genotypes. We observed similarly increased ORs for exposure across PON1Q192R genotypes, but no differences across PON1C-108T genotypes. The largest ORs were estimated for exposed carriers of both PON1192QQ and PON155MM (OR range, 2.84-3.57). Several functional PON1 variants may act together to modify PD risk for ambient OP exposures. While either PON1L55M or PON1Q192R may be sufficient to identify increased susceptibility, carriers of both slow metabolizer variants seem most susceptible to OP exposures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Lyso-DGTS lipid isolated from microalgae enhances PON1 activities in vitro and in vivo, increases PON1 penetration into macrophages and decreases cellular lipid accumulation.

PubMed

Dahli, Loureen; Atrahimovich, Dana; Vaya, Jacob; Khatib, Soliman

2018-04-16

High-density lipoprotein (HDL) plays an important role in preventing atherosclerosis. The antioxidant effect of HDL is mostly associated with paraoxonase 1 (PON1) activity. Increasing PON1 activity using nutrients might improve HDL function and quality and thus, decrease atherosclerotic risk. We previously isolated and identified a novel active compound, lyso-DGTS (C20:5,0) from Nannochloropsis sp. ethanol extract. In the present study, its effect on PON1 activities was examined and the mechanism by which the compound affects PON1 activity was explored. Lyso-DGTS elevated recombinant PON1 (rePON1) lactonase and esterase activities in a dose- and time-responsive manner, and further stabilized and preserved rePON1 lactonase activity. Incubation of lyso-DGTS with human serum for 4 h at 37°C also increased PON1 lactonase activity in a dose-responsive manner. Using tryptophan-fluorescence-quenching assay, lyso-DGTS was found to interact with rePON1 spontaneously with negative free energy (ΔG = -22.87 kJ mol -1 at 25°C). Thermodynamic parameters and molecular modeling calculations showed that the main interaction of lyso-DGTS with the enzyme is through a hydrogen bond with supporting van der Waals interactions. Furthermore, lyso-DGTS significantly increased rePON1 influx into macrophages and prevented lipid accumulation in macrophages stimulated with oxidized low-density lipid dose-dependently. In vivo supplementation of lyso-DGTS to the circulation of mice fed a high-fat diet via osmotic mini-pumps implanted subcutaneously significantly increased serum PON1 lactonase activity and decreased serum glucose concentrations to the level of mice fed a normal diet. Our findings suggest a beneficial effect of lyso-DGTS on increasing PON1 activity and thus, improving HDL quality and atherosclerotic risk factors. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Role of paraoxonase (PON1) status in pesticide sensitivity: genetic and temporal determinants.

PubMed

Furlong, Clement E; Cole, Toby B; Jarvik, Gail P; Pettan-Brewer, Christina; Geiss, Gary K; Richter, Rebecca J; Shih, Diana M; Tward, Aaron D; Lusis, Aldons J; Costa, Lucio G

2005-08-01

Individual differences in detoxication capacities for specific organophosphorous (OP) compounds are due largely to differences in catalytic efficiency or abundance of the HDL-associated enzyme, paraoxonase (PON1). First, we provide evidence that children less than 2 years of age represent a particularly susceptible population for OP exposure due to low abundance of PON1 and variable onset of plasma PON1 activity. Second, we describe studies examining the neurotoxic effects of chronic, low-level OP pesticide exposure in mice. PON1 knockout (PON1(-/-)) and wild-type mice were exposed chronically (PN4 to PN21) to low levels of chlorpyrifos oxon (CPO). Endpoints included cholinesterase activity, histopathology, gene expression, and behavior. Even at PN4, when PON1 levels were low in wild-type mice, PON1(-/-) mice were more sensitive to inhibition of brain cholinesterase by CPO. At PN22, and persisting as long as 4 months, chronic developmental exposure to 0.18 mg/kg/d or 0.25 mg/kg/d CPO resulted in perinuclear vacuolization of cells in a discrete area of the neocortex and irregular distribution of neurons in the cortical plate, with an increase in the number of affected cells at 0.25mg/kg/d. Third, we describe a transgenic mouse model in which human transgenes encoding either hPON1Q192 or hPON1R192 were expressed at equal levels in place of mouse PON1. The developmental onset of expression followed the mouse time course and was identical for the two transgenes, allowing these mice to be used to assess the importance of the Q192R polymorphism during development. Adult mice expressing hPON1R192 were significantly more resistant than hPON1Q192 mice to CPO toxicity. Our studies indicate that children less than 2 years old, especially those homozygous for PON1Q192, would be predicted to be particularly susceptible to CPO toxicity.

Risk of carotid atherosclerosis is associated with low serum paraoxonase (PON1) activity among arsenic exposed residents in Southwestern Taiwan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, W.-F.; Sun, C.-W.; Cheng, T.-J.

2009-04-15

To understand whether human paraoxonase 1 (PON1) would modulate the risk for arsenic-related atherosclerosis, we studied 196 residents from an arseniasis-endemic area in Southwestern Taiwan and 291 age- and sex-matched residents from a nearby control area where arsenic exposure was found low. Carotid atherosclerosis was defined by a carotid artery intima-media wall thickness (IMT) of > 1.0 mm. Prevalence of carotid atherosclerosis was increased in the arseniasis-endemic area as compared to the control area after adjustment for conventional risk factors (OR = 2.20, p < 0.01). The prevalence was positively associated with cumulative arsenic exposure (mg/L-year) in a dose-dependent manner.more » Multiple logistic regression analysis showed that in the endemic group, low serum PON1 activity was an independent risk factor for atherosclerosis (OR = 4.18 low vs. high, p < 0.05). For those of low PON1 activity and high cumulative arsenic exposure, the odds ratio for the prevalence of atherosclerosis was further increased up to 5.68 (p < 0.05). No significant association was found between atherosclerosis and four polymorphisms of the PON gene cluster (PON1 - 108C/T, PON1 Q192R, PON2 A148G, PON2 C311S). However, genetic frequencies of certain alleles including PON1 Q192, PON2 G148 and PON2 C311 were found increased in the endemic group as compared to the controls and a general Chinese population, indicating a possible survival selection in the endemic group after a long arsenic exposure history. Our results showed a significant joint effect between arsenic exposure and serum PON1 activity on carotid atherosclerosis, suggesting that subjects of low PON1 activity may be more susceptible to arsenic-related cardiovascular disease.« less

Identification of paraoxonase 3 in rat liver microsomes: purification and biochemical properties.

PubMed Central

Rodrigo, Lourdes; Gil, Fernando; Hernandez, Antonio F; Lopez, Olga; Pla, Antonio

2003-01-01

Three paraoxonase genes (PON1, PON2 and PON3) have been described so far in mammals. Although considerable information is available regarding PON1, little is known about PON2 and PON3. PON3 has been isolated recently from rabbit serum [Draganov, Stetson, Watson, Billecke and La Du (2000) J. Biol. Chem. 275, 33435-33442] and liver [Ozols (1999) Biochem. J. 338, 265-275]. In the present study, we have identified the presence of PON3 in rat liver microsomes and a method for the purification to homogeneity is presented. PON3 has been purified 177-fold to apparent homogeneity with a final specific activity of 461 units/mg using a method consisting of seven steps: solubilization of the microsomal fraction, hydroxyapatite adsorption, chromatography on DEAE-Sepharose CL-6B, non-specific affinity chromatography on Cibacron Blue 3GA, two DEAE-cellulose steps and a final affinity chromatography on concanavalin A-Sepharose. SDS/PAGE of the final preparation indicated a single protein-staining band with an apparent molecular mass of 43 kDa. The isolated protein was identified by nanoelectrospray MS. Internal amino acid sequences of several peptides were determined and compared with those of human, rabbit and mouse PON3, showing a high similarity. Some biochemical properties of PON3 were also studied, including optimum pH, K(m) and heat and pH stability. PMID:12946270

Paraoxonase in Persian Gulf War veterans.

PubMed

Hotopf, Matthew; Mackness, Michael Ian; Nikolaou, Vasilis; Collier, David A; Curtis, Charles; David, Anthony; Durrington, Paul; Hull, Lisa; Ismail, Khalida; Peakman, Mark; Unwin, Catherine; Wessely, Simon; Mackness, Bharti

2003-07-01

Serum paraoxonase (PON1) is responsible for the metabolism of organophosphates in serum, and PON1 activity is a major determinant of their toxicity in humans. There have been reports linking lowered PON1 activity to physical symptoms after deployment to the Persian Gulf War (PGW) of 1990 to 1991. Therefore, the object of this study was to determine (1) whether PON1 activity was decreased among symptomatic PGW veterans compared with asymptomatic PGW veterans and (2) to determine whether PGW veterans as a whole had lower PON1 activity compared with other military control groups. This was a case control study nested in occupational cohort study of military personnel. Four groups of military personnel were identified from a large epidemiological study of health effects of deployment to the PGW and Bosnia: (1) symptomatic PGW veterans, n = 115; (2) healthy PGW veterans, n = 95; (3) symptomatic Bosnia peacekeeping veterans, n = 52; and (4) symptomatic nondeployed military controls, n = 85. The main outcome measures were PON1 activity and genotype for PON1-55 and -192. We found significant differences in PON1 activity among these four groups, and although the two Gulf groups did not differ in PON1 activity, those deployed to the Gulf had significantly lower PON1 activity compared with the non-PGW groups (median difference = 70.9; 95% CI: 20.2, 121.5, P = 0.012). These differences were not explained by a range of potential confounders, or differences in PON1 coding region polymorphisms. PON1 activity is reduced in PGW veterans compared with military control groups. The effect is independent of ill health in PGW veterans.

Monitoring technique for a hybrid PS/WDM-PON by using a tunable OTDR and FBGs

NASA Astrophysics Data System (ADS)

Hann, Swook; Yoo, Jun-sang; Park, Chang-Soo

2006-05-01

A monitoring technique for hybrid passive optical networks (PON) is presented. The technique is based on the remote sensing of fibre Bragg gratings (FBGs) using a tunable optical time domain reflectometer (OTDR). The FBG would help discern an individual event during the monitoring of the hybrid PON in collaboration with the information provided by the Rayleigh backscattered power. The hybrid architecture of passive splitter-PON and WDM-PON can be analysed by the monitoring method by using the tunable OTDR and FBGs at the central office under the in-service state of PON.

Paraoxonase-2 and paraoxonase-3: comparison of mRNA expressions in the placentae of unexplained intrauterine growth restricted and noncomplicated pregnancies.

PubMed

Dikbas, Levent; Yapca, Omer Erkan; Dikbas, Neslihan; Gundogdu, Cemal

2017-05-01

Recent evidence suggests that oxidative stress is involved in the pathophysiology of many human diseases. It has been demonstrated that oxidative stress is associated with intrauterine growth restriction (IUGR), and the depletion of placental antioxidant systems has been suggested as a key factor in this disease. Our aims were to explore the possible role of antioxidant paraoxonase-2 (PON2) and paraoxonase-3 (PON3) in the pathophysiology of unexplained IUGR. We have studied the expression of mRNA for PON2, PON3 in placental tissues by using RT-qPCR. Two groups, consisting of normal (n = 18) and unexplained IUGR pregnancies (n = 20) were compared. Our results demonstrated that there were no significant differences in the mRNA expressions of PON2, PON3 between the two groups (p = 0.28, p = 0.90, respectively). PON2 and PON3 were down-regulated in IUGR. Antenatal steroid therapy had no effect on the expression mRNA in placentae of unexplained IUGR pregnancies compared to non-treated group. These results suggest that PON2, PON3 mRNA levels were not changed significantly in placentae of IUGR when compared to normal pregnant women.

Structure, chaperone-like activity and allergenicity profile of bovine caseins upon peroxynitrite modification: New evidences underlying mastitis pathomechanisms.

PubMed

Sadeghian, Tanaz; Tavaf, Zohreh; Oryan, Ahmad; Shokouhi, Raheleh; Pourpak, Zahra; Moosavi-Movahedi, Ali Akbar; Yousefi, Reza

2018-01-01

Mastitis, an inflammatory reaction frequently develops in response to intra-mammary bacterial infection‌‌, may induce the generation of peroxynitrite (PON)‌ which is a highly potent reactive oxygen and nitrogen species. Caseins as the intrinsically unfolded proteins seem feasible substrates to react with PON. Therefore, in the current study, structural and functional aspects of both β-casein (β-CN) and whole casein fraction (WCF) were evaluated after PON modification, using a variety of techniques. Modification of the bovine caseins with PON results in an important enhancement in the carbonyl, nitrotryptophan, nitrotyrosine and dityrosine content of these proteins‌. The results of fluorescence and far UV-CD assessments suggested significant structural alteration of caseins upon PON-modification. The chaperone-like activity of β-casein was significantly altered after PON modification. The results of scanning electron microscopy suggest that bovine caseins display unique morphological features after treatment with PON. Also, the PON-modified caseins preserved their allergenicity profile and displayed partial resistance against digestion by the pancreatic proteases. Ascorbic acid, an important antioxidant component of milk, was also capable to significantly prevent the PON-induced structural damages in bovine milk caseins. In conclusion, our results suggest that PON may have significant role in the structural and functional alteration of milk caseins. Also, the PON-induced structural damaging effects of caseins might be effectively prevented by a sufficient level of milk antioxidant components particularly by ascorbic acid. Copyright © 2017 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Androutsopoulos, Vasilis P.; Kanavouras, Konstantinos; Tsatsakis, Aristidis M., E-mail: aris@med.uoc.gr

Organophosphate pesticides are a class of compounds that are widely used in agricultural and rural areas. Paraoxonase 1 (PON1) is a phase-I enzyme that is involved in the hydrolysis of organophosphate esters. Environmental poisoning by organophosphate compounds has been the main driving force of previous research on PON1 enzymes. Recent discoveries in animal models have revealed the important role of the enzyme in lipid metabolism. However although PON1 function is well established in experimental models, the contribution of PON1 in neurodegenerative diseases remains unclear. In this minireview we summarize the involvement of PON1 genotypes in the occurrence of Parkinson's disease,more » Alzheimer's disease and amyotrophic lateral sclerosis. A brief overview of latest epidemiological studies, regarding the two most important PON1 coding region polymorphisms PON1-L55M and PON1-Q192R is presented. Positive and negative associations of PON1 with disease occurrence are reported. Notably the MM and RR alleles contribute a risk enhancing effect for the development of some neurodegenerative diseases, which may be explained by the reduced lipoprotein free radical scavenging activity that may give rise to neuronal damage, through distinct mechanism. Conflicting findings that fail to support this postulate may represent the human population ethnic heterogeneity, different sample size and environmental parameters affecting PON1 status. We conclude that further epidemiological studies are required in order to address the exact contribution of PON1 genome in combination with organophosphate exposure in populations with neurodegenerative diseases.« less

Somatotopic location of corticospinal tract at pons in human brain: a diffusion tensor tractography study.

PubMed

Hong, Ji Heon; Son, Su Min; Jang, Sung Ho

2010-07-01

No diffusion tensor tractography (DTT) study has yet investigated the somatotopic location of the corticospinal tract (CST) at the pons. In the current study, we used DTT to investigate the somatotopic location of the CST at the pons in the human brain. We recruited 25 healthy volunteers for this study. Diffusion tensor images (DTIs) were scanned using 1.5-T; CSTs for the hand and leg were obtained using FMRIB software. Normalized DTT was reconstructed using the Montreal Neurological Institute echo-planar imaging template supplied with the SPM. Individual DTI data were calculated as a pixel unit at the upper and lower pons. Relative average location of the highest probability point of the CST for the hand was 47.70%, with the standard from the midline to the most lateral point of the upper pons, and 35.87% at the lower pons. For the leg, the CST was located at 56.82% at the upper pons and 40.63% at the lower pons. For the anteroposterior direction from the most anterior point of the pons to the most anterior point of the fourth ventricle, the CST for the hand was located at 42.30% at the upper pons and 36.18% at the lower pons. For the leg, the CST was located at 45.68% and 39.01%, respectively. We found that the hand somatotopy of the CST was located at the antero-medial portion at the pons and that the leg somatotopy of the CST was located postero-laterally to the hand somatotopy of the CST. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Transcriptional regulation of human paraoxonase 1 by PXR and GR in human hepatoma cells.

PubMed

Ponce-Ruiz, N; Rojas-García, A E; Barrón-Vivanco, B S; Elizondo, G; Bernal-Hernández, Y Y; Mejía-García, A; Medina-Díaz, I M

2015-12-25

Human paraoxonase 1 (PON1) is A-esterase synthesized in the liver and secreted into the plasma, where it associates with HDL. PON1 acts as an antioxidant preventing lipid oxidation and detoxifies a wide range of substrates, including organophosphate compounds. The variability of PON1 (enzyme activity/serum levels) has been attributed to internal and external factors. However, the molecular mechanisms involved in the transcriptional regulation of PON1 have not been well-studied. The aim of this study was to evaluate and characterize the transcriptional activation of PON1 by nuclear receptors (NR) in human hepatoma cells. In silico analysis was performed on the promoter region of PON1 to determine the response elements of NR. Real-time PCR was used to evaluate the effect of specific NR ligands on the mRNA levels of genes regulated by NR and PON1. The results indicated that NR response elements had 95% homology to pregnenolone (PXR), glucocorticoids (GR), retinoic acid (RXR) and peroxisomes proliferator-activated receptor alpha (PPARα). Treatments with Dexamethasone (GR ligand), Rifampicin (PXR ligand) and TCDD (AhR ligand) increased the mRNA levels of PON1 at 24 and 48 h. We showed that the activation of GR by Dexamethasone results in PON1 gene induction accompanied by an increase in activity levels. In conclusion, these results demonstrate that GR regulates PON1 gene transcription through directly binding to NR response elements at -95 to -628 bp of the PON1 promoter. This study suggests new molecular mechanisms for the transcriptional regulation of PON1 through a process involving the activation of PXR. Copyright © 2015 Elsevier B.V. All rights reserved.

Regulatory effects of dioxin-like and non-dioxin-like PCBs and other AhR ligands on the antioxidant enzymes paraoxonase 1/2/3.

PubMed

Shen, Hua; Robertson, Larry W; Ludewig, Gabriele

2016-02-01

Paraoxonase 1 (PON1), an antioxidant enzyme, is believed to play a critical role in many diseases, including cancer. PCBs are widespread environmental contaminants known to induce oxidative stress and cancer and to produce changes in gene expression of various pro-oxidant and antioxidant enzymes. Thus, it appeared of interest to explore whether PCBs may modulate the activity and/or gene expression of PON1 as well. In this study, we compared the effects of dioxin-like and non-dioxin-like PCBs and of various aryl hydrocarbon receptor (AhR) ligands on PON1 regulation and activity in male and female Sprague-Dawley rats. Our results demonstrate that (i) the non-dioxin-like PCB154, PCB155, and PCB184 significantly reduced liver and serum PON1 activities, but only in male rats; (ii) the non-dioxin-like PCB153, the most abundant PCB in many matrices, did not affect PON1 messenger RNA (mRNA) level in the liver but significantly decreased serum PON1 activity in male rats; (iii) PCB126, an AhR ligand and dioxin-like PCB, increased both PON1 activities and gene expression; and (iv) even though three tested AhR ligands induced CYP1A in several tissues to a similar extent, they displayed differential effects on the three PONs and AhR, i.e., PCB126 was an efficacious inducer of PON1, PON2, PON3, and AhR in the liver, while 3-methylcholantrene induced liver AhR and lung PON3, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent AhR agonist, increased only PON3 in the lung, at the doses and exposure times used in these studies. These results show that PCBs may have an effect on the antioxidant protection by paraoxonases in exposed populations and that regulation of gene expression through AhR is highly diverse.

Serum paraoxonase level and paraoxonase polymorphism in patients with acromegaly.

PubMed

Arpaci, Dilek; Karakas Celik, Sevim; Can, Murat; Ermiş, Esra; Kuzu, Fatih; Kokturk, Furuzan; Hamamcioglu, Ayse Ceylan; Dursun, Ahmet; Bayraktaroglu, Taner

2016-11-01

Acromegalic patients have increased cardiometabolic risk factors due to an elevation of growth hormone (GH) levels. Human serum paraoxonase (PON), a high-density lipoprotein (HDL)-related enzyme, is one of the major bioscavengers and decreases the oxidation of low-density lipoprotein (LDL), a key regulator in the pathogenesis of atherosclerosis. In this study, we investigated a potential relationship between serum PON levels or PON polymorphisms and acromegaly. A total of 48 acromegalic patients and 44 healthy controls were included in this study. Serum GH levels, insulin-like growth factor-1 levels and lipid profiles were measured. Serum PON levels, as well as PON 1 L55M and Q192R gene polymorphisms, were examined. No significant differences were found in terms of age, gender, presence of diabetes, serum LDL cholesterol (LDL-C), HDL-C, or triglyceride levels between the case and control groups (P > 0.05). A statistically significant difference was found in serum PON levels between the cases and controls (P = 0.007). The median serum PON level was 101 ± 63.36 U/l in the case group and 63 ± 60.50 U/l in the control group. There was a significant correlation between serum PON levels and IGF-1 levels (P = 0.004, r = 0.319); however, no significant differences were found in PON1 L55M and PON Q192R polymorphisms between the patients and controls (P = 0.607 and P = 0.308, respectively). In addition, no significant differences were found in serum PON levels in acromegalic patients who were and were not in remission (P = 0.385), nor between those with PON1 L55M and Q192R polymorphisms (P = 0.161 and P = 0.336, respectively). Elevated serum PON levels were detected in acromegalic patients, independently of their remission status. This suggests protective effects for cardiometabolic risk parameters.

Impact of backreflections on single-fiber bidirectional wavelength-division-multiplexing passive optical networks (WDM-PONs)

NASA Astrophysics Data System (ADS)

Gao, Shiyu

With increased demand for bandwidth-hungry applications such as video-on-demand, wavelength-division-multiplexing passive optical network (WDM-PON) has become a strong contender in overcoming the last mile bottle neck. However, the wide-scale deployment of WDM-PONs has been delayed mainly due to the high cost of wavelength-specific optical components. To realize cost-effective WDM-PONs, various wavelength-independent, so called colorless architectures, have been developed so that all the subscribers can have identical optical network units (ONUs). In such WDM-PONs, however, single-fiber bidirectional transmission results in degradation of system performance caused by interference between the signals and backreflections. This thesis investigates the impact of backreflections on single-fiber bidirectional WDM-PONs. A WDM-PON with various optical line terminals (OLTs) and colorless ONU configurations is presented. The dependence of the power penalty, caused by backreflections, on a variety of parameters is investigated. This includes parameters such as the source linewidths, receiver bandwidth, transmission line loss (TLL), ONU gain, chirp effect at the ONU and optical return loss (ORL), in various WDM-PON configurations. The WDM-PON with continuous wave (CW) seed light and remodulation schemes are both presented and studied experimentally. The impacts of the backreflections on the single-fiber bidirectional WDM-PON with various OLT and ONU configurations are compared and analyzed accordingly.

Multi-PON access network using a coarse AWG for smooth migration from TDM to WDM PON

NASA Astrophysics Data System (ADS)

Shachaf, Y.; Chang, C.-H.; Kourtessis, P.; Senior, J. M.

2007-06-01

An interoperable access network architecture based on a coarse array waveguide grating (AWG) is described, displaying dynamic wavelength assignment to manage the network load across multiple PONs. The multi-PON architecture utilizes coarse Gaussian channels of an AWG to facilitate scalability and smooth migration path between TDM and WDM PONs. Network simulations of a cross-operational protocol platform confirmed successful routing of individual PON clusters through 7 nm-wide passband windows of the AWG. Furthermore, polarization-dependent wavelength shift and phase errors of the device proved not to impose restrain on the routing performance. Optical transmission tests at 2.5 Gbit/s for distances up to 20 km are demonstrated.

PON1 promoter polymorphisms contribute to PCOS susceptibility and phenotypic outcomes in Indian women.

PubMed

Dadachanji, Roshan; Shaikh, Nuzhat; Patil, Anushree; Shah, Nalini; Mukherjee, Srabani

2018-06-30

Polycystic ovary syndrome is a common endocrinopathy characterized by anovulatory infertility, hyperandrogenism, insulin resistance and oxidative stress, which predisposes affected women to reproductive and cardiometabolic complications in later life. We have investigated the association of PON1 promoter polymorphisms with PCOS susceptibility, PON1 activity and its related traits in Indian women. The genotypic and allelic frequency distribution of only -907G/C polymorphism in PON1 promoter showed significant difference between non-hyperandrogenic control and PCOS women, and was significantly associated with reduced susceptibility to PCOS, considering the recessive model. PON1 lactonase and arylesterase activities were also significantly decreased in women with PCOS compared to controls. Further, PON1 promoter polymorphisms were linked to altered insulin and testosterone levels in hyperandrogenic and non-hyperandrogenic women with PCOS. This study highlights PON1 as an important candidate gene influencing genetic pathophysiology of PCOS. Copyright © 2018 Elsevier B.V. All rights reserved.

Surveillance technique for hybrid WDM/PS-PON using a tunable OTDR

NASA Astrophysics Data System (ADS)

Hann, Swook; Yoo, Jun-sang; Park, Chang-soo

2005-05-01

A surveillance technique for passive optical networks (PON) is presented. The technique is based on the remote sensing of fiber Bragg grating using a tunable OTDR. Hybrid architecture of WDM and passive splitter-PON can be analyzed by the surveillance method at the central office under in-service state of PON.

Survivable architectures for time and wavelength division multiplexed passive optical networks

NASA Astrophysics Data System (ADS)

Wong, Elaine

2014-08-01

The increased network reach and customer base of next-generation time and wavelength division multiplexed PON (TWDM-PONs) have necessitated rapid fault detection and subsequent restoration of services to its users. However, direct application of existing solutions for conventional PONs to TWDM-PONs is unsuitable as these schemes rely on the loss of signal (LOS) of upstream transmissions to trigger protection switching. As TWDM-PONs are required to potentially use sleep/doze mode optical network units (ONU), the loss of upstream transmission from a sleeping or dozing ONU could erroneously trigger protection switching. Further, TWDM-PONs require its monitoring modules for fiber/device fault detection to be more sensitive than those typically deployed in conventional PONs. To address the above issues, three survivable architectures that are compliant with TWDM-PON specifications are presented in this work. These architectures combine rapid detection and protection switching against multipoint failure, and most importantly do not rely on upstream transmissions for LOS activation. Survivability analyses as well as evaluations of the additional costs incurred to achieve survivability are performed and compared to the unprotected TWDM-PON. Network parameters that impact the maximum achievable network reach, maximum split ratio, connection availability, fault impact, and the incremental reliability costs for each proposed survivable architecture are highlighted.

VX hydrolysis by human serum paraoxonase 1: a comparison of experimental and computational results.

PubMed

Peterson, Matthew W; Fairchild, Steven Z; Otto, Tamara C; Mohtashemi, Mojdeh; Cerasoli, Douglas M; Chang, Wenling E

2011-01-01

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an in vivo countermeasure, it has been suggested that increasing HuPON1's organophosphorous hydrolase activity by one or two orders of magnitude would make the enzyme suitable for this purpose. The binding interaction between HuPON1 and VX has recently been modeled, but the mechanism for VX hydrolysis is still unknown. In this study, we created a transition state model for VX hydrolysis (VX(ts)) in water using quantum mechanical/molecular mechanical simulations, and docked the transition state model to 22 experimentally characterized HuPON1 variants using AutoDock Vina. The HuPON1-VX(ts) complexes were grouped by reaction mechanism using a novel clustering procedure. The average Vina interaction energies for different clusters were compared to the experimentally determined activities of HuPON1 variants to determine which computational procedures best predict how well HuPON1 variants will hydrolyze VX. The analysis showed that only conformations which have the attacking hydroxyl group of VX(ts) coordinated by the sidechain oxygen of D269 have a significant correlation with experimental results. The results from this study can be used for further characterization of how HuPON1 hydrolyzes VX and design of HuPON1 variants with increased activity against VX.

VX Hydrolysis by Human Serum Paraoxonase 1: A Comparison of Experimental and Computational Results

PubMed Central

Peterson, Matthew W.; Fairchild, Steven Z.; Otto, Tamara C.; Mohtashemi, Mojdeh; Cerasoli, Douglas M.; Chang, Wenling E.

2011-01-01

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an in vivo countermeasure, it has been suggested that increasing HuPON1's organophosphorous hydrolase activity by one or two orders of magnitude would make the enzyme suitable for this purpose. The binding interaction between HuPON1 and VX has recently been modeled, but the mechanism for VX hydrolysis is still unknown. In this study, we created a transition state model for VX hydrolysis (VXts) in water using quantum mechanical/molecular mechanical simulations, and docked the transition state model to 22 experimentally characterized HuPON1 variants using AutoDock Vina. The HuPON1-VXts complexes were grouped by reaction mechanism using a novel clustering procedure. The average Vina interaction energies for different clusters were compared to the experimentally determined activities of HuPON1 variants to determine which computational procedures best predict how well HuPON1 variants will hydrolyze VX. The analysis showed that only conformations which have the attacking hydroxyl group of VXts coordinated by the sidechain oxygen of D269 have a significant correlation with experimental results. The results from this study can be used for further characterization of how HuPON1 hydrolyzes VX and design of HuPON1 variants with increased activity against VX. PMID:21655255

Genistein as a potential inducer of the anti-atherogenic enzyme paraoxonase-1: studies in cultured hepatocytes in vitro and in rat liver in vivo

PubMed Central

Schrader, Charlotte; Ernst, Insa M A; Sinnecker, Heike; Soukup, Sebastian T; Kulling, Sabine E; Rimbach, Gerald

2012-01-01

A number of cardioprotective effects, including the reduced oxidation of the low-density lipoprotein (LDL) particles, have been attributed to dietary soy isoflavones. Paraoxonase 1 (PON1), an enzyme mainly synthesized in the liver, may exhibit anti-atherogenic activity by protecting LDL from oxidation. Thus, dietary and pharmacological inducers of PON1 may decrease cardiovascular disease risk. Using a luciferase reporter gene assay we screened different flavonoids for their ability to induce PON1 in Huh7 hepatocytes in culture. Genistein was the most potent flavonoid with regard to its PON1-inducing activity, followed by daidzein, luteolin, isorhamnetin and quercetin. Other flavonoids such as naringenin, cyanidin, malvidin and catechin showed only little or no PON1-inducing activity. Genistein-mediated PON1 transactivation was partly inhibited by the oestrogen-receptor antagonist fulvestrant as well as by the aryl hydrocarbon receptor antagonist 7-ketocholesterol. In contrast to genistein, the conjugated genistein metabolites genistein-7-glucuronide, genistein-7-sulfate and genistein-7,4′-disulfate were only weak inducers of PON1 transactivation. Accordingly, dietary genistein supplementation (2 g/kg diet over three weeks) in growing rats did not increase hepatic PON1 mRNA and protein levels as well as plasma PON1 activity. Thus, genistein may be a PON1 inducer in cultured hepatocytes in vitro, but not in rats in vivo. PMID:22304296

Adenovirus-mediated human paraoxonase1 gene transfer to provide protection against the toxicity of the organophosphorus pesticide toxicant diazoxon.

PubMed

Duysen, E G; Parikh, K; Aleti, V; Manne, V; Lockridge, O; Chilukuri, N

2011-03-01

Human paraoxonase1 (hPON1) is a potential therapeutic against the toxicity of organophosphorus (OP) pesticides and chemical warfare nerve agents. We tested whether PON1 gene transfer using adenovirus provides protection against the toxicity of the OP diazoxon. Using an adenovirus construct containing hPON1 gene, we showed elevated levels of recombinant hPON1 in vitro in 293A cells and in vivo in mice. The recombinant enzyme was secreted by 293A cells into culture medium and into the systemic circulation of mice. Western blotting revealed that the virally expressed hPON1 had the expected molecular weight of 45 kDa. Recombinant hPON1 in mice was in complex with mouse high-density lipoprotein (HDL) and migrated more slowly than endogenous hPON1 in the human HDL complex. Mice injected with adenovirus expressed PON1 at 600-3480 U ml(-1) on day 5 post-treatment, which is 8-50-fold above endogenous. Six mice expressing hPON1 survived 2LD(50) doses of diazoxon. Four of the six mice survived a second dose of diazoxon (for a total of 4LD(50)) administered 24 h later. In contrast, none of the three mice in the control group survived one 2LD(50) dose. These results show that hPON1 in mice functions as a prophylactic and offers significant protection against lethal doses of diazoxon.

Postoperative occipital neuralgia in posterior upper cervical spine surgery: a systematic review.

PubMed

Guan, Qing; Xing, Fei; Long, Ye; Xiang, Zhou

2017-11-07

Postoperative occipital neuralgia (PON) after upper cervical spine surgery can cause significant morbidity and may be overlooked. The causes, presentation, diagnosis, management, prognosis, and prevention of PON were reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. English-language studies and case reports published from inception to 2017 were retrieved. Data on surgical procedures, incidence, cause of PON, management, outcomes, and preventive technique were extracted. Sixteen articles, including 591 patients, were selected; 93% of the patients with PON underwent C1 lateral mass screw (C1LMS) fixation, with additional 7% who underwent occipitocervical fusion without C1 fixation. PON had an incidence that ranged from 1 to 35% and was transient in 34%, but persistent in 66%. Five articles explained the possible causes. The primary presentation was constant or paroxysmal burning pain located mainly in the occipital and upper neck area and partially extending to the vertical, retroauricular, retromandibular, and forehead zone. Treatment included medications, nerve block, revision surgery, and nerve stimulation. Two prospective studies compared the effect of C2 nerve root transection on PON. PON in upper cervical spine surgery is a debilitating complication and was most commonly encountered by patients undergoing C1LMS fixation. The etiology of PON is partially clear, and the pain could be persistent and hard to cure. Reducing the incidence of PON can be realized by improving technique. More high-quality prospective studies are needed to define the effect of C2 nerve root transection on PON.

Rare coding variation in paraoxonase-1 is associated with ischemic stroke in the NHLBI Exome Sequencing Project.

PubMed

Kim, Daniel Seung; Crosslin, David R; Auer, Paul L; Suzuki, Stephanie M; Marsillach, Judit; Burt, Amber A; Gordon, Adam S; Meschia, James F; Nalls, Mike A; Worrall, Bradford B; Longstreth, W T; Gottesman, Rebecca F; Furlong, Clement E; Peters, Ulrike; Rich, Stephen S; Nickerson, Deborah A; Jarvik, Gail P

2014-06-01

HDL-associated paraoxonase-1 (PON1) is an enzyme whose activity is associated with cerebrovascular disease. Common PON1 genetic variants have not been consistently associated with cerebrovascular disease. Rare coding variation that likely alters PON1 enzyme function may be more strongly associated with stroke. The National Heart, Lung, and Blood Institute Exome Sequencing Project sequenced the coding regions (exomes) of the genome for heart, lung, and blood-related phenotypes (including ischemic stroke). In this sample of 4,204 unrelated participants, 496 had verified, noncardioembolic ischemic stroke. After filtering, 28 nonsynonymous PON1 variants were identified. Analysis with the sequence kernel association test, adjusted for covariates, identified significant associations between PON1 variants and ischemic stroke (P = 3.01 × 10(-3)). Stratified analyses demonstrated a stronger association of PON1 variants with ischemic stroke in African ancestry (AA) participants (P = 5.03 × 10(-3)). Ethnic differences in the association between PON1 variants with stroke could be due to the effects of PON1Val109Ile (overall P = 7.88 × 10(-3); AA P = 6.52 × 10(-4)), found at higher frequency in AA participants (1.16% vs. 0.02%) and whose protein is less stable than the common allele. In summary, rare genetic variation in PON1 was associated with ischemic stroke, with stronger associations identified in those of AA. Increased focus on PON1 enzyme function and its role in cerebrovascular disease is warranted.

Paraoxonase promoter and intronic variants modify risk of sporadic amyotrophic lateral sclerosis

PubMed Central

Cronin, Simon; Greenway, Matthew J; Prehn, Jochen H M; Hardiman, Orla

2007-01-01

Background The paraoxonases, PON1–3, play a major protective role both against environmental toxins and as part of the antioxidant defence system. Recently, non‐synonymous coding single nucleotide polymorphisms (SNPs), known to lower serum PON activity, have been associated with sporadic ALS (SALS) in a Polish population. A separate trio based study described a detrimental allele at the PON3 intronic variant INS2+3651 (rs10487132). Association between PON gene cluster variants and SALS requires external validation in an independent dataset. Aims To examine the association of the promoter SNPs PON1−162G>A and PON1−108T>C; the non‐synonymous functional SNPs PON1Q192R and L55M and PON2C311S and A148G; and the intronic marker PON3INS2+3651A>G, with SALS in a genetically homogenous population. Methods 221 Irish patients with SALS and 202 unrelated control subjects were genotyped using KASPar chemistries. Statistical analyses and haplotype estimations were conducted using Haploview and Unphased software. Multiple permutation testing, as implemented in Unphased, was applied to haplotype p values to correct for multiple hypotheses. Results Two of the seven SNPs were associated with SALS in the Irish population: PON155M (OR 1.52, p = 0.006) and PON3INS2+3651 G (OR 1.36, p = 0.03). Two locus haplotype analysis showed association only when both of these risk alleles were present (OR 1.7, p = 0.005), suggesting a potential effect modification. Low functioning promoter variants were observed to influence this effect when compared with wild‐type. Conclusions These data provide additional evidence that genetic variation across the paroxanase loci may be common susceptibility factors for SALS. PMID:17702780

Toxicity of chlorpyrifos and chlorpyrifos oxon in a transgenic mouse model of the human paraoxonase (PON1) Q192R polymorphism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Toby B.; Walter, Betsy J.; Shih, Diana M.

2005-08-01

The Q192R polymorphism of paraoxonase (PON1) has been shown to affect hydrolysis of organophosphorus compounds. The Q192 and R192 alloforms exhibit equivalent catalytic efficiencies of hydrolysis for diazoxon, the oxon form of the pesticide (DZ). However, the R192 alloform has a higher catalytic efficiency of hydrolysis than does the Q192 alloform for chlorpyrifos oxon (CPO), the oxon form of the pesticide chlorpyrifos (CPS). The current study examined the relevance of these observations for in-vivo exposures to chlorpyrifos and chlorpyrifos oxon. Methods Using a transgenic mouse model we examined the relevance of the Q192R polymorphism for exposure to CPS and CPOmore » in vivo. Transgenic mice were generated that expressed either human PON1Q192 or PON1R192 at equivalent levels, in the absence of endogenous mouse PON1. Dose-response and time course experiments were performed on adult mice exposed dermally to CPS or CPO. Morbidity and acetylcholinesterase (AChE) activity in the brain and diaphragm were determined in the first 24 h following exposure. Results Mice expressing PON1Q192 were significantly more sensitive to CPO, and to a lesser extent CPS, than were mice expressing PON1R192. The time course of inhibition following exposure to 1.2 mg/kg CPO revealed maximum inhibition of brain AChE at 6?12 h, with PON1R192, PON1Q192, and PON1? /? mice exhibiting 40, 70 and 85% inhibition, respectively, relative to control mice. The effect of PON1 removal on the dose?response curve for CPS exposure was remarkably consistent with a PBPK/PD model of CPS exposure. Conclusion These results indicate that individuals expressing only the PON1Q192 allele would be more sensitive to the adverse effects of CPO or CPS exposure, especially if they are expressing a low level of plasma PON1Q192.« less

Paraoxonase-1 genetic polymorphisms and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Satyender; Kumar, Vivek; Thakur, Sachin

2011-04-15

Human paraoxonase 1 (PON1) is a lipoprotein-associated enzyme involved in the detoxification of organophosphate pesticides (OPs) by hydrolyzing the bioactive oxons. Polymorphisms of the PON1 gene are responsible for variation in the expression and catalytic activity of PON1 enzyme. In the present study, we have determined (a) the prevalence of two common PON1 polymorphisms, (b) the activity of PON1 and acetylcholinesterase enzymes, and (c) the influence of PON1 genotypes and phenotypes variation on DNA damage in workers exposed to OPs. We examined 230 subjects including 115 workers exposed to OPs and an equal number of normal healthy controls. The resultsmore » revealed that PON1 activity toward paraoxon (179.19 {+-} 39.36 vs. 241.52 {+-} 42.32 nmol/min/ml in controls) and phenylacetate (112.74 {+-} 17.37 vs. 134.28 {+-} 25.49 {mu}mol/min/ml in controls) was significantly lower in workers than in control subjects (p < 0.001). No significant difference was observed in the distribution of genotypes and allelic frequencies of PON1{sub 192}QR (Gln/Arg) and PON1{sub 55}LM (Leu/Met) in workers and control subjects (p > 0.05). The PON1 activity toward paraoxonase was found to be significantly higher in the R/R (Arg/Arg) genotypes than Q/R (Gln/Arg) and lowest in Q/Q (Gln/Gln) genotypes in both workers and control subjects (p < 0.001). For PON1{sub 55}LM (Leu/Met), PON1 activity toward paraoxonase was observed to be higher in individuals with L/L (Leu/Leu) genotypes and lowest in individuals with M/M (Met/Met) genotypes in both groups (p < 0.001). No influence of PON1 genotypes and phenotypes was seen on the activity of acetylcholinesterase and arylesterase. The DNA damage was observed to be significantly higher in workers than in control subjects (p < 0.05). Further, the individuals who showed least paraoxonase activity i.e., those with (Q/Q [Gln/Gln] and M/M [Met/Met]) genotypes showed significantly higher DNA damage compared to other isoforms in workers exposed to OPs (p < 0.05). The results indicate that the individuals with PON1 Q/Q and M/M genotypes are more susceptible toward genotoxicity. In conclusion, the study suggests wide variation in enzyme activities and DNA damage due to polymorphisms in PON1 gene, which might have an important role in the identification of individual risk factors in workers occupationally exposed to OPs.« less

A Highly Flexible and Efficient Passive Optical Network Employing Dynamic Wavelength Allocation

NASA Astrophysics Data System (ADS)

Hsueh, Yu-Li; Rogge, Matthew S.; Yamamoto, Shu; Kazovsky, Leonid G.

2005-01-01

A novel and high-performance passive optical network (PON), the SUCCESS-DWA PON, employs dynamic wavelength allocation to provide bandwidth sharing across multiple physical PONs. In the downstream, tunable lasers, an arrayed waveguide grating, and coarse/fine filtering combine to create a flexible new optical access solution. In the upstream, several distributed and centralized schemes are proposed and investigated. The network performance is compared to conventional TDM-PONs under different traffic models, including the self-similar traffic model and the transaction-oriented model. Broadcast support and deployment issues are addressed. The network's excellent scalability can bridge the gap between conventional TDM-PONs and WDM-PONs. The powerful architecture is a promising candidate for next generation optical access networks.

Paraoxonase 1 (PON1) gene-108C>T and p.Q192R polymorphisms and arylesterase activity of the enzyme in patients with dementia.

PubMed

Bednarska-Makaruk, Małgorzata Ewa; Krzywkowski, Tomasz; Graban, Alla; Lipczyńska-Łojkowska, Wanda; Bochyńska, Anna; Rodo, Maria; Wehr, Hanna; Ryglewicz, Danuta Krystyna

2013-01-01

Paraoxonase 1 (PON1) activity was determined using phenylacetate as substrate (arylesterase activity) in 304 individuals with dementia--136 recognised as probable Alzheimer's disease (AD), 64 as dementia of vascular origin (VaD) and 104 as mixed dementia (MD) and in 129 persons without symptoms of dementia and in a good general health. -108C>T polymorphism in the PON1 gene promoter and p.Q192R polymorphism in the coding region were identified. PON1 activity was significantly lower in demented patients as compared with controls particularly in dementia of a neurodegenerative character (AD and MD). The prevalence of PON1-108T allele carriers was significantly higher in the AD group than in controls. The frequencies of the p.Q192R genotypes did not differ significantly between the investigated groups. An association of the rare T-R haplotype with dementia, particularly with dementia of the neurodegenerative type, was found. Multivariate regression analysis showed a significant association of PON1 activity with PON1 -108C>T and p.Q192R polymorphisms. The influence not only of promoter -108C>T, but also of p.Q192R polymorphism on PON1 arylesterase activity was observed. One has to admit that this kind of polymorphism does not preclude interference with the enzyme activity. It could be concluded that the PON1 gene promoter polymorphism plays an additional role in Alzheimer's disease development. It seems however that PON1 activity has a dominating influence on the dementia risk.

Rare coding variation in paraoxonase-1 is associated with ischemic stroke in the NHLBI Exome Sequencing Project[S

PubMed Central

Kim, Daniel Seung; Crosslin, David R.; Auer, Paul L.; Suzuki, Stephanie M.; Marsillach, Judit; Burt, Amber A.; Gordon, Adam S.; Meschia, James F.; Nalls, Mike A.; Worrall, Bradford B.; Longstreth, W. T.; Gottesman, Rebecca F.; Furlong, Clement E.; Peters, Ulrike; Rich, Stephen S.; Nickerson, Deborah A.; Jarvik, Gail P.

2014-01-01

HDL-associated paraoxonase-1 (PON1) is an enzyme whose activity is associated with cerebrovascular disease. Common PON1 genetic variants have not been consistently associated with cerebrovascular disease. Rare coding variation that likely alters PON1 enzyme function may be more strongly associated with stroke. The National Heart, Lung, and Blood Institute Exome Sequencing Project sequenced the coding regions (exomes) of the genome for heart, lung, and blood-related phenotypes (including ischemic stroke). In this sample of 4,204 unrelated participants, 496 had verified, noncardioembolic ischemic stroke. After filtering, 28 nonsynonymous PON1 variants were identified. Analysis with the sequence kernel association test, adjusted for covariates, identified significant associations between PON1 variants and ischemic stroke (P = 3.01 × 10−3). Stratified analyses demonstrated a stronger association of PON1 variants with ischemic stroke in African ancestry (AA) participants (P = 5.03 × 10−3). Ethnic differences in the association between PON1 variants with stroke could be due to the effects of PON1Val109Ile (overall P = 7.88 × 10−3; AA P = 6.52 × 10−4), found at higher frequency in AA participants (1.16% vs. 0.02%) and whose protein is less stable than the common allele. In summary, rare genetic variation in PON1 was associated with ischemic stroke, with stronger associations identified in those of AA. Increased focus on PON1 enzyme function and its role in cerebrovascular disease is warranted. PMID:24711634

Interaction between organophosphate pesticide exposure and PON1 activity on thyroid function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacasana, Marina, E-mail: marina.lacasana.easp@juntadeandalucia.e; CIBER de Epidemiologia y Salud Publica; Lopez-Flores, Inmaculada

Organophosphate pesticides are widely used in agricultural purposes. Recently, a few studies have demonstrated the ability of these chemicals to alter the function of the thyroid gland in human. Moreover, the paraoxonase-1 enzyme (PON1) plays an important role in the toxicity of some organophosphate pesticides, with low PON1 activity being associated with higher pesticide sensitivity. This study evaluates the interaction between exposure to organophosphate compounds and PON1 enzyme activity on serum levels of TSH and thyroid hormones in a population of workers occupationally exposed to pesticides. A longitudinal study was conducted on a population of floriculture workers from Mexico, duringmore » two periods of high and low-intensity levels of pesticide application. A structured questionnaire was completed by workers containing questions on sociodemographic characteristics and other variables of interest. Urine and blood samples were taken, and biomarkers of exposure (dialkylphosphates), susceptibility (PON1 polymorphisms and activity) and effect (thyroid hormone levels) were determined. Interaction between dialkylphosphates and PON1 polymorphisms or PON1 activity on hormone levels was evaluated by generalized estimating equation (GEE) models. A significant interaction was found between serum diazoxonase activity and total dialkylphosphates ({Sigma}DAP) on TSH levels. Thus, when PON1 activity was increased we observed a decrease in the percentage of variation of TSH level for each increment in one logarithmic unit of the {Sigma}DAP levels. This interaction was also observed with the PON1{sub 192}RR genotype. These results suggest a stronger association between organophosphate pesticides and thyroid function in individuals with lower PON1 activity.« less

Human Paraoxonase1 Hydrolysis of Nanomolar Chlorpyrifos-oxon Concentrations is Unaffected by Phenotype or Q192R Genotype

PubMed Central

Coombes, R. Hunter; Meek, Edward C.; Dail, Mary Beth; Chambers, Howard W.; Chambers, Janice E.

2016-01-01

The organophosphorus insecticide chlorpyrifos has been widely used. Its active metabolite chlorpyrifos-oxon (CPO) is a potent anticholinesterase and is detoxified by paraoxonase-1 (PON1). PON1 activity is influenced by numerous factors including a Q192R polymorphism. Using forty human blood samples bearing homozygous genotypes and either high or low activity phenotypes (as determined by high concentration assays of paraoxon and diazoxon hydrolysis) the serum PON1 hydrolysis of high (320 μM) and low (178 nM) CPO concentrations was assessed using direct or indirect spectrophotometric methods, respectively. PON1 activity at high CPO concentration reflected the phenotype and genotype differences; subjects with the high activity phenotype and homozygous for the PON1R192 alloform hydrolyzed significantly more CPO than subjects with the low activity phenotype and/or PON1Q192 alloform (High RR=11023±722, Low RR=9467±798, High QQ=8809±672, Low QQ=6030±1015 μmoles CPO hydrolyzed/min/L serum). However, PON1 hydrolysis of CPO at the lower, more environmentally relevant concentration showed no significant differences between the PON1192 genotypes and/or between high and low activity phenotypes (High RR=231±27, Low RR=219±52, High QQ=193±59, Low QQ=185±43 nmoles CPO/min/L serum). Low CPO concentrations were probably not saturating, so PON1 did not display maximal velocity and the PON1 genotype/phenotype might not influence the extent of metabolism at environmental exposures. PMID:25093614

Downregulation of human paraoxonase 1 (PON1) by organophosphate pesticides in HepG2 cells.

PubMed

Medina-Díaz, Irma Martha; Ponce-Ruiz, Néstor; Ramírez-Chávez, Bryana; Rojas-García, Aurora Elizabeth; Barrón-Vivanco, Briscia S; Elizondo, Guillermo; Bernal-Hernández, Yael Y

2017-02-01

Paraoxonase 1 (PON1) is a calcium-dependent esterase synthesized primarily in the liver and secreted into the plasma where it is associated with high-density lipoproteins (HDL). PON1 hydrolyzes and detoxifies some toxic metabolites of organophosphorus compounds (OPs) such as methyl parathion and chlorpyrifos. Thus, PON1 activity and expression levels are important for determining susceptibility against OPs poisoning. Some studies have demonstrated that OPs can modulate gene expression through interactions with nuclear receptors. In this study, we evaluated the effects of methyl parathion and chlorpyrifos on the modulation of PON1 in Human Hepatocellular Carcinoma (HepG2) cells by real-time PCR, PON1 activity assay, and western blot. The results showed that the treatments with methyl parathion and chlorpyrifos decreased PON1 mRNA and immunoreactive protein and increased inflammatory cytokines in HepG2 cells. The effects of methyl parathion and chlorpyrifos on the downregulation of PON1 gene expression in HepG2 cells may provide evidence of OPs cytotoxicity related to oxidative stress and an inflammatory response. A decrease in the expression of the PON1 gene may increase the susceptibility to OPs intoxication and the risk of diseases related to inflammation and oxidative stress. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 490-500, 2017. © 2016 Wiley Periodicals, Inc.

Lithium anode for lithium-air secondary batteries

NASA Astrophysics Data System (ADS)

Imanishi, Nobuyuki; Hasegawa, Satoshi; Zhang, Tao; Hirano, Atushi; Takeda, Yasuo; Yamamoto, Osamu

The lithium ion conducting solid lithium phosphorous nitride (LiPON) has been sputtered on the water-stable NASICON-type lithium ion conducting solid electrolyte Li 1+ x+ yAl xTi 2- xP 3- ySi yO 12 (LATP). The stability and the interface resistance of the Li-Al/LiPON/LATP/LiPON/Li-Al cell have been examined. It is shown that the LiPON film protects LATP from reacting with the Li-Al alloy. The impedance of the Li-Al/LiPON/LATP/LiPON/Li-Al cell has been measured in the temperature range 25-80 °C. The total cell resistance is about 8600 Ω cm 2 at room temperature and 360 Ω cm 2 at 80 °C. The analysis of the impedance profiles suggests that the Li-Al/LiPON interface resistance is dominant at lower temperatures. The LATP plate immersed in water for 1 month shows only a slight degradation in the conductivity.

Transcriptional regulation of human Paraoxonase 1 by nuclear receptors.

PubMed

Ponce-Ruiz, N; Murillo-González, F E; Rojas-García, A E; Mackness, Mike; Bernal-Hernández, Y Y; Barrón-Vivanco, B S; González-Arias, C A; Medina-Díaz, I M

2017-04-25

Paraoxonase 1 (PON1) is a calcium-dependent lactonase synthesized primarily in the liver and secreted into the plasma, where it is associates with high density lipoproteins (HDL). PON1 acts as antioxidant preventing low-density lipoprotein (LDL) oxidation, a process considered critical in the initiation and progression of atherosclerosis. Additionally, PON1 hydrolyzes and detoxifies some toxic metabolites of organophosphorus compounds (OPs). Thus, PON1 activity and expression levels are important for determining susceptibility to OPs intoxication and risk of developing diseases related to inflammation and oxidative stress. Increasing evidence has demonstrated the modulation of PON1 expression by many factors is due to interaction with nuclear receptors (NRs). Here, we briefly review the studies in this area and discuss the role of nuclear receptors in the regulation of PON1 expression, as well as how understanding these mechanisms may allow us to manipulate PON1 levels to improve drug efficacy and treat disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of serum paraoxonase-1 (PON1) activity on follicular development and pregnancy rate in cattle.

PubMed

Castro, Natália A; Pfeifer, Luiz F M; Andrade, Jéssica S; Rincón, Joao A A; Pegoraro, Ligia M Cantarelli; Schneider, Augusto

2018-01-01

Paraoxonase-1 (PON1) activity has been associated with improvement in ovarian function in early postpartum dairy cows and improved in vitro embryo development. The aim of the current study was to evaluate the potential association among PON1 activity and follicular growth, diameter of the preovulatory follicle and pregnancy per artificial insemination (AI) service in cattle. In Experiment 1, cows (n=33) were subjected to an estradiol-progesterone based protocol to control time of ovulation. Starting on Day 8 of the protocol, follicular growth and serum PON1 activity were monitored. Cows were separated according to the occurrence of ovulation into two groups: Ovulatory (Ov; n=22) and Anovulatory (Anov; n=11). The serum activity of PON1 was not different between Ov and Anov cows (P=0.94). In addition, using a regression model there was no effect of serum PON1 activity on the diameter of dominant follicle (r 2 =0.00; P=0.99). In Experiment 2, cows (n=193) were submitted to the same hormonal protocol as in Experiment 1. On the day of the timed artificial insemination (TAI), the diameter of dominant follicle was evaluated and blood samples were collected for analysis of PON1 activity. According to the serum PON1 activity, cows were divided into three groups: Low (<70U/mL), Medium (70-90U/mL) or High (>90U/mL) PON1 activity. The overall pregnancy rate was 62.7% (121/193), with no difference among PON1 activity groups. Additionally, using a regression model there was no effect of serum PON1 activity on the diameter of the preovulatory follicle (r 2 =0.03; P=0.65) and pregnancy rate (r 2 =0.005; P=0.94). The results of this study indicate that there is no effect of serum PON1 activity on the diameter of preovulatory follicle or establishment of pregnancy in cows submitted to time of ovulation synchronization protocols. Copyright © 2017 Elsevier B.V. All rights reserved.

Stereo-specific Synthesis of Analogs of Nerve Agents And Their Utilization For Selection And Characterization of Paraoxonase (PON1) Catalytic Scavengers

PubMed Central

Ashani, Y.; Gupta, R.D.; Goldsmith, M.; Silman, I.; Sussman, J.L.; Tawfik, D. S.; Leader, H.

2010-01-01

Fluorogenic organophosphate inhibitors of acetylcholinesterase (AChE) homologous in structure to nerve agents provide useful probes for high throughput screening of mammalian paraoxonase (PON1) libraries generated by directed evolution of an engineered PON1 variant with wild-type like specificity (rePON1). Wt PON1 and rePON1 hydrolyze preferentially the less-toxic RP enantiomers of nerve agents and of their fluorogenic surrogates containing the fluorescent leaving group, 3-cyano-7-hydroxy-4-methylcoumarin (CHMC). To increase the sensitivity and reliability of the screening protocol so as to directly select rePON1 clones displaying stereo-preference towards the toxic SP enantiomer, and to determine accurately Km and kcat values for the individual isomers, two approaches were used to obtain the corresponding SP and RP isomers: (a) stereo-specific synthesis of the O-ethyl, O-n-propyl, and O-i-propyl analogs; (b) enzymic resolution of a racemic mixture of O-cyclohexyl methylphosphonylated CHMC. The configurational assignments of the SP and RP isomers, as well as their optical purity, were established by X-ray diffraction, reaction with sodium fluoride, hydrolysis by selected rePON1 variants, and inhibition of AChE. The SP configuration of the tested surrogates was established for the enantiomer with the more potent anti-AChE activity, with SP/RP inhibition ratios of 10–100, whereas the RP isomers of the O-ethyl and O-n-propyl were hydrolyzed by wt rePON1 about 600- and 70-fold faster, respectively, than the SP counterpart. Wt rePON1-induced RP/SP hydrolysis ratios for the O-cyclohexyl and O-i-propyl analogs are estimated to be ≫1000. The various SP enantiomers of O-alkyl-methylphosphonyl esters of CHMC provide suitable ligands for screening rePON1 libraries, and can expedite identification of variants with enhanced catalytic proficiency towards the toxic nerve agents. PMID:20303930

Methodological constraints in interpreting serum paraoxonase-1 activity measurements: an example from a study in HIV-infected patients.

PubMed

Parra, Sandra; Marsillach, Judit; Aragonès, Gerard; Rull, Anna; Beltrán-Debón, Raúl; Alonso-Villaverde, Carlos; Joven, Jorge; Camps, Jordi

2010-03-25

Paraoxonase-1 (PON1) is an antioxidant enzyme that attenuates the production of the monocyte chemoattractant protein-1 (MCP-1) in vitro. Although oxidation and inflammation are closely related processes, the association between PON1 and MCP-1 has not been completely characterised due, probably, to that the current use of synthetic substrates for PON1 measurement limits the interpretation of the data. In the present study, we explored the relationships between the circulating levels of PON1 and MCP-1 in human immunodeficiency virus-infected patients in relation to the multifunctional capabilities of PON1. We measured selected variables in 227 patients and in a control group of 409 participants. Serum PON1 esterase and lactonase activities were measured as the rates of hydrolysis of paraoxon and of 5-(thiobutyl)-butyrolactone, respectively. Oxidised LDL and MCP-1 concentrations were determined by enzyme-linked immunosorbent assay. High-density lipoproteins cholesterol, apolipoprotein A-I, and C-reactive protein concentrations were measured by standard automated methods. There were significant relationships between PON1 activity and several indices of oxidation and inflammation in control subjects and in infected patients. However, these relationships varied not only with disease status but also on the type of substrate used for PON1 measurement. The present study is a cautionary tale highlighting that results of clinical studies on PON1 may vary depending on the methods used as well as the disease studied. Until more specific methods using physiologically-akin substrates are developed for PON1 measurement, we suggest the simultaneous employment of at least two different substrates in order to improve the reliability of the results obtained.

Effect of Lipoic Acid on Serum Paraoxonase-1 and Paraoxonase-3 Protein Levels and Activities in Diabetic Rats.

PubMed

Ozgun, E; Ozgun, G S; Gokmen, S S; Eskıocak, S; Sut, N; Akıncı, M; Goncu, E; Cakır, E

2016-02-05

The aim of the present study was to investigate the effect of streptozotocin-induced diabetes mellitus and lipoic acid treatment on serum paraoxonase-1 and paraoxonase-3 protein levels and paraoxonase, arylesterase and lactonase activities.36 rats were equally and randomly divided into 4 groups as control, lipoic acid, diabetes and diabetes+lipoic acid. To induce diabetes, a single dose of streptozotocin (40 mg/kg) was injected intraperitoneally to diabetes and diabetes+lipoic acid groups. Lipoic acid (10 mg/kg/day) was injected intraperitoneally for 14 days to lipoic acid and diabetes+lipoic acid groups. Serum PON1 and PON3 protein levels were measured by western blotting. Serum paraoxonase, arylesterase and lactonase activities were determined by the measuring initial rate of substrate (paraoxon, phenylacetate and dihydrocoumarin) hydrolysis.Streptozotocin-induced diabetes mellitus caused a significant decrease whereas lipoic acid treatment caused a significant increase in serum PON1 and PON3 protein levels and paraoxonase, arylesterase and lactonase activities. The increase percent of serum PON3 protein was higher than that of serum PON1 protein and the increase percent of serum lactonase activity was higher than that of serum paraoxonase and arylesterase activities in diabetes+lipoic acid group.We can report that, like PON1 protein, PON3 protein and actually its lactonase activity may also have a role as an antioxidant in diabetes mellitus and lipoic acid treatment may be useful for the prevention of the atherosclerotic complications of diabetes by increasing serum PON1 and PON3 protein levels and serum enzyme activities. © Georg Thieme Verlag KG Stuttgart · New York.

PON1 and Neurodevelopment in Children from the CHAMACOS Study Exposed to Organophosphate Pesticides in Utero

PubMed Central

Eskenazi, Brenda; Huen, Karen; Marks, Amy; Harley, Kim G.; Bradman, Asa; Barr, Dana Boyd; Holland, Nina

2010-01-01

Background Paraoxonase 1 (PON1) detoxifies oxon derivatives of some organophosphate (OP) pesticides, and its genetic polymorphisms influence enzyme activity and quantity. We previously reported that maternal urinary concentrations of dialkyl phosphate (DAP) metabolites, a marker of OP pesticide exposure, were related to poorer mental development and maternally reported symptoms consistent with pervasive developmental disorder (PDD) in 2-year-olds participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study. Objective We determined whether PON1 genotypes and enzyme measurements were associated with child neurobehavioral development and whether PON1 modified the association of in utero exposure to OPs (as assessed by maternal DAPs) and neurobehavior. Methods We measured DAP concentrations in maternal urine during pregnancy, PON1192 and PON1−108 genotypes in mothers and children, and arylesterase (ARYase) and paraoxonase (POase) in maternal, cord, and 2-year-olds’ blood. We assessed 353 2-year-olds on the Mental Development Index (MDI) and Psychomotor Development Index (PDI) of the Bayley Scales of Infant Development and queried their mothers on the Child Behavior Checklist to obtain a score for PDD. Results Children with the PON1−108T allele had poorer MDI scores and somewhat poorer PDI scores. Children were less likely to display PDD when they or their mothers had higher ARYase activity and when their mothers had higher POase activity. The association between DAPs and MDI scores was strongest in children with PON1−108T allele, but this and other interactions between DAPs and PON1 polymorphisms or enzymes were not significant. Conclusion PON1 was associated with child neurobehavioral development, but additional research is needed to confirm whether it modifies the relation with in utero OP exposure. PMID:21126941

The paraoxonase-1 pathway is not a major bioactivation pathway of clopidogrel in vitro

PubMed Central

Ancrenaz, V; Desmeules, J; James, R; Fontana, P; Reny, J-L; Dayer, P; Daali, Y

2012-01-01

BACKGROUND AND PURPOSE Clopidogrel is a prodrug bioactivated by cytochrome P450s (CYPs). More recently, paraoxonase-1 (PON1) has been proposed as a major contributor to clopidogrel metabolism. The purpose of this study was to assess the relative contribution of CYPs and PON1 to clopidogrel metabolism in vitro. EXPERIMENTAL APPROACH Clopidogrel metabolism was studied in human serum, recombinant PON1 enzyme (rePON1), pooled human liver microsomes (HLMs), HLMs with the CYP2C19*1/*1 genotype and HLMs with the CYP2C19*2/*2 genotype. Inhibition studies were also performed using specific CYP inhibitors and antibodies. Clopidogrel and its metabolites were measured using LC/MS/MS method. KEY RESULTS PON1 activity was highest in the human serum and there was no difference in PON1 activity between any of the HLM groups. The production of clopidogrel's active metabolite (clopidogrel-AM) from 2-oxo-clopidogrel in pooled HLMs was approximately 500 times that in serum. When 2-oxo-clopidogrel was incubated with rePON1, clopidogrel-AM was not detected. Clopidogrel-AM production from 2-oxo-clopidogrel was lower in CYP2C19*2/*2 HLMs compared with CYP2C19*1/*1 HLMs, while PON1 activity in HLMs with both genotypes was similar. Moreover, incubation with inhibitors of CYP3A, CYP2B6 and CYP2C19 significantly reduced clopidogrel bioactivation while a PON1 inhibitor, EDTA, had only a weak inhibitory effect. CONCLUSION AND IMPLICATIONS This in vitro study shows that the contribution of PON1 to clopidogrel metabolism is limited at clinically relevant concentrations. Moreover, CYP2C19, CYP2B6 and CYP3A play important roles in the bioactivation of clopidogrel. PMID:22428615

IgG-Paraoxonase-1 Fusion Protein for Targeted Drug Delivery Across the Human Blood-Brain Barrier

PubMed Central

Boado, Ruben J.; Zhang, Yun; Zhang, Yufeng; Wang, Yuntao; Pardridge, William M.

2009-01-01

Paraoxonase (PON)-1 is the most potent human protein with organophosphatase activity against organophosphate (OP) toxins. OP compounds readily cross the blood-brain barrier (BBB), and have lethal mechanisms of action within the brain. The production of a brain penetrating form of human PON1, which crosses the BBB, is possible with the re-engineering of the enzyme as a fusion protein with a monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb crosses the BBB via the endogenous insulin receptor, and acts as a molecular Trojan horse to ferry the PON1 into brain. The human PON1 was fused to the carboxyl terminus of the heavy chain of the chimeric HIRMAb. COS cells were dual transfected with the heavy chain gene and the light chain gene, and the HIRMAb-PON1 fusion protein was affinity purified with protein A chromatography. Western blotting with antibodies to human IgG or human PON1 showed the heavy chain of the HIRMAb-PON1 fusion protein was 40 kDa larger than the heavy chain of the chimeric HIRMAb. The ED50 of binding to the HIR extracellular domain was 0.55 ± 0.07 nM and 1.1 ±0.1 nM, respectively, for the chimeric HIRMAb and the HIRMAb-PON1 fusion protein. The PON1 enzyme activity of the fusion protein was approximately 25% of the enzyme activity in human plasma, based on a fluorometric enzymatic assay. In conclusion, human PON1 has been re-engineered as an IgG-organophosphatase fusion protein that penetrates the human BBB. PMID:19434854

Reversal of noradrenergic depletion and lipid peroxidation in the pons after brain injury correlates with motor function recovery in rats.

PubMed

Bueno-Nava, Antonio; Montes, Sergio; DelaGarza-Montano, Paloma; Alfaro-Rodriguez, Alfonso; Ortiz, Ascencion; Gonzalez-Pina, Rigoberto

2008-09-26

Functional impairment after brain injury (BI) has been attributed to the inhibition of regions that are related to the injured site. Therefore, noradrenaline (NA) is thought to play a critical role in recovery from motor injury. However, the mechanism of this recovery process has not been completely elucidated. Moreover, the locus coeruleus (LC) projects from the pons through the rat sensorimotor cortex, and injury axotomizes LC fibers, depressing NA function. This was tested by measuring lipid peroxidation (LP) in the pons after sensorimotor cortex injury. Depression of function in the pons would be expected to alter areas receiving pontine efferents. Male Wistar rats were divided into three groups: control (n=16), injured (n=10) and recovering (n=16), and they were evaluated using a beam-walking assay between 2 and 20 days after cortical injury. We performed measures of NA and LP in both sides of the pons and cerebellum. We found a decrease of NA in the pons and the cerebellum, and a concomitant increase in the motor deficit and LP in the pons of injured animals. Recovering rats had NA and LP levels that were very similar to those observed in control rats. These observations suggest that the mechanism of remote inhibition after BI involves lipid peroxidation, and that the NA decrease found in the cerebellum of injured animals is mediated by a noradrenergic depression in the pons, or in areas receiving NA projections from the pons.

Paraoxonase Enzyme Protects Retinal Pigment Epithelium from Chlorpyrifos Insult

PubMed Central

Jasna, Jagan Mohan; Anandbabu, Kannadasan; Bharathi, Subramaniam Rajesh; Angayarkanni, Narayanasamy

2014-01-01

Retinal pigment epithelium (RPE) provides nourishment and protection to the eye. RPE dysfunction due to oxidative stress and inflammation is one of the major reason for many of the retinal disorders. Organophosphorus pesticides are widely used in the agricultural, industrial and household activities in India. However, their effects on the eye in the context of RPE has not been studied. In this study the defense of the ARPE19 cells exposed to Chlorpyrifos (1 nM to 100 µM) in terms of the enzyme paraoxonase (PON) was studied at 24 hr and 9 days of treatment. Chlorpyrifos was found to induce oxidative stress in the ARPE19 cells as seen by significant increase in ROS and decrease in glutathione (GSH) levels without causing cell death. Tissue resident Paraoxonase 2 (PON2) mRNA expression was elevated with chlorpyrifos exposure. The three enzymatic activities of PON namely, paraoxonase (PONase), arylesterase (PON AREase) and thiolactonase (PON HCTLase) were also found to be significantly altered to detoxify and as an antioxidant defense. Among the transcription factors regulating PON2 expression, SP1 was significantly increased with chlorpyrifos exposure. PON2 expression was found to be crucial as ARPE19 cells showed a significant loss in their ability to withstand oxidative stress when the cells were subjected to chlorpyrifos after silencing PON2 expression. Treatment with N-acetyl cysteine positively regulated the PON 2 expression, thus promoting the antioxidant defense put up by the cells in response to chlorpyrifos. PMID:24979751

The Q192R polymorphism of the paraoxonase-1 (PON1) gene is associated with susceptibility to gestational diabetes mellitus in the Greek population.

PubMed

Pappa, Kalliopi I; Gazouli, Maria; Anastasiou, Eleni; Loutradis, Dimitrios; Anagnou, Nicholas P

2017-08-01

A key factor protecting from oxidative stress in gestational diabetes mellitus (GDM) and in type 2 diabetes (T2D) is paraoxonase-1 (PON1). Inconclusive and limited data exist regarding the effect of a coding polymorphism (Q192R) of the PON1 gene in conferring susceptibility to both states. In the present study, we investigated the association between the PON1 gene and the risk for GDM in the Greek population and assessed for the first time its transcriptional efficiency. We studied 185 women with GDM and 104 non-diabetic controls for the PON1 polymorphism. For PON1 mRNA expression, peripheral leucocytes were harvested from 20 GDM and 20 control women, harboring different genotypes for the polymorphism, using real-time quantitative PCR. The RR genotype and the R allele of the PON1 Q192R polymorphism were significantly associated with an increased risk for GDM (p = 0.012 and p < 0.0001, respectively). Furthermore, there was no statistical correlation between the individual metabolic parameters tested and the three genotypes. Finally, the expression levels of PON1 mRNA in GDM patients did not exhibit any statistical difference compared with normal controls (p = 0.138). These data independently document that the Q192R polymorphism is closely associated with GDM susceptibility, while the PON1 gene expression is not impaired in GDM.

Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

PubMed Central

Boshtam, Maryam; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

2013-01-01

Introduction. Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health. PMID:24167374

Serum paraoxonase 1 activity is associated with fatty acid composition of high density lipoprotein.

PubMed

Boshtam, Maryam; Razavi, Amirnader Emami; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

2013-01-01

Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω 6 fatty acids of HDL. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health.

WDM PONs based on colorless technology

NASA Astrophysics Data System (ADS)

Saliou, Fabienne; Simon, Gael; Chanclou, Philippe; Pizzinat, Anna; Lin, Huafeng; Zhou, Enyu; Xu, Zhiguang

2015-12-01

Wavelength Division Multiplexing (WDM) Passive Optical Network (PON) is foreseen to be part of the Next Generation Passive Optical Networks. Business and mobile fronthaul networks already express the need to develop WDM PONs in the access segment. Fixed wavelength transceivers based on Coarse WDM are already available to respond to today's market needs but Dense WDM technologies will be needed and colorless technologies are essential to provide simple and cost-effective WDM PON systems. We propose in this paper to demonstrate the capabilities of a DWDM PON system prototype based on self-seeded RSOAs and designed to transmit CPRI over 60 km of fiber at 2.5 Gbit/s.

Some indazoles reduced the activity of human serum paraoxonase 1, an antioxidant enzyme: in vitro inhibition and molecular modeling studies.

PubMed

Alım, Zuhal; Kılıç, Deryanur; Demir, Yeliz

2018-05-09

Paraoxonase 1 (PON1: EC 3.1.8.1) is a vital antioxidant enzyme against mainly atherosclerosis and many other diseases associated with oxidative stress. Thus, studies related to PON1 have an important place in the pharmacology. In this study, we aimed to evaluate the in vitro inhibition effects of some indazoles on the activity of human PON1. PON1 was purified from human serum with a specific activity of 5000 U/mg and 13.50% yield by using simple chromatographic methods. The indazoles showed K i values in a range of 26.0 ± 3.00-111 ± 31.0 μM against hPON1. All these indazoles exhibited competitive inhibition. In addition, molecular docking studies were performed in order to assess the probable binding mechanisms into the active site of hPON1. Molecular modeling studies confirmed our results. Inhibition of PON1 by indazoles supplies a verification to further consideration of limitation dosage of indazole molecule groups as drug.

Paraoxonase 1 192 and 55 polymorphisms in osteosarcoma.

PubMed

Ergen, Arzu; Kılıcoglu, Onder; Ozger, Harzem; Agachan, Bedia; Isbir, Turgay

2011-08-01

Paraoxonase is an HDL-associated enzyme that plays a preventive role against oxidative stres. Previous studies suggested that involved an amino acid substitution at position 192 gives rise to two alloenzymes with a low activity (Q allele) and a high activity (R allele) towards paraoxon. There also exists a second polymorphism of the human PON1 gene affecting amino acid 55, giving rise to a leucine (L-allele) substitution for methionine (M-allele). PON1 gene polymorphisms were studied in 50 patients with osteosarcoma and 50 healthy controls. Paraoxonase genotypes were determined by PCR-RFLP. We found a reduction in the frequency of PON1 192 R allele in patients (P=0.015). Besides, PON1 192 wild type QQ genotype (P=0.015) and PON1 55 wild type L allele (P=0.001) were higher in patients compared to healthy controls. PON1 192 QQ genotype was associated with osteosarcoma in multivariate logistic regression analysis. Our findings have suggested that PON1 192 wild type genotypes may be associated with a risk of developing osteosarcoma.

Paraoxonase 1 and its relationship with pesticide biomarkers in indigenous Mexican farmworkers.

PubMed

Bernal-Hernández, Yael Yvette; Medina-Díaz, Irma Martha; Barrón-Vivanco, Briscia Socorro; Robledo-Marenco, María de Lourdes; Girón-Pérez, Manuel Iván; Pérez-Herrera, Norma Elena; Quintanilla-Vega, Betzabet; Cerda-Flores, Ricardo; Rojas-García, Aurora Elizabeth

2014-03-01

Biomarkers of pesticide toxicity and paraoxonase 1 (PON1) phenotype and genotypes were evaluated in indigenous Mexican farmworkers exposed mainly to organophosphate (OP) pesticides. Acetylcholinesterase, butyrylcholinesterase, and PON1 activities--arylesterase and CMPAase activities--were evaluated spectrophotometrically. PON1 55 and 192 polymorphisms were determined by real-time polymerase chain reaction. Hematological parameters were evaluated using a cytometer. Butyrylcholinesterase and arylesterase activities were lower in farmworkers, who also showed lower levels of leukocytes but higher percentages of lymphocytes when compared with the nonexposed group. Our results showed a high frequency of OP, high hydrolysis-related PON1 alleles (LL/QR and LL/RR) in the study population. An association was observed between CMPAase activity and PON1Q192R polymorphism. Our results suggest that pesticide exposure modifies biochemical and hematological biomarkers in the study population, and that the phenotype of PON1 (CMPAase) is a sensible susceptibility biomarker of OP pesticide toxicity.

Association of lead, cadmium and mercury with paraoxonase 1 activity and malondialdehyde in a general population in Southern Brazil.

PubMed

Almeida Lopes, Ana Carolina Bertinde; Urbano, Mariana Ragassi; Souza-Nogueira, André de; Oliveira-Paula, Gustavo H; Michelin, Ana Paula; Carvalho, Maria de Fátima H; Camargo, Alissana Ester Iakmiu; Peixe, Tiago Severo; Cabrera, Marcos Aparecido Sarria; Paoliello, Monica Maria Bastos

2017-07-01

Metal exposure is associated with increased oxidative stress (OS), which is considered an underlying mechanism of metal-induced toxicity. Malondialdehyde (MDA) is a final product of lipid peroxidation, and it has been extensively used to evaluate metal-induced OS. Pro-oxidant effects produced by metals can be mitigated by paraoxonase 1 (PON1), an antioxidant enzyme known to prevent cardiovascular disease and atherosclerosis. Among other factors, the Q192R polymorphism and the exposure to heavy metals have been known to alter PON1 activity. Here, we evaluated the association of blood lead (Pb), cadmium (Cd) and mercury (Hg) levels with PON1 activity, and with MDA concentrations in a randomly selected sample of Brazilian adults aged 40 years or older, living in an urban area in Southern Brazil. A total of 889 subjects were evaluated for blood Pb and Cd levels, and 832 were tested for Hg. Geometric mean of blood Pb, Cd and Hg was 1.93μg/dL, 0.06μg/L and 1.40μg/L, respectively. PON1 activity was significantly different among various genotypes: QQ (PON1=121.4U/mL), QR (PON1=87.5U/mL), and RR (PON1=55.2U/mL), p<0.001. PON1 genotypes were associated only with Cd blood levels. Those with QR genotype had Cd concentrations higher (0.07μg/L) than those with the RR genotype (0.04μg/L) with p=0.034. However, PON1 activity was not significantly associated with metal concentrations. Cluster analysis showed that men who reported to be current smokers and drinkers with higher blood Pb and Cd levels, had significantly lower PON1 activity than non-smokers or -drinkers, and women with lower Pb and Cd levels. RR genotype carriers had lower PON1 activity than those with the QR genotype, and had higher levels of Pb and Cd compared with other genotype carriers. For blood Hg, no association with PON1 activity or genotype was noted. We found low levels of Pb, Cd and Hg in environmentally exposed Brazilian adults. Cd concentrations were increased in subjects with QR genotype. Those with RR genotype had lower PON1 activity and higher levels of Pb and Cd than other genotype carriers. The results of cluster analysis suggested that smoking status exerts a significant influence on PON1 activity. Other studies with environmentally exposed populations are required to further clarify whether low blood levels of metals influence OS biomarkers. Copyright © 2017 Elsevier Inc. All rights reserved.

Postprandial serum triacylglycerols and oxidative stress in mice after consumption of fish oil, soy oil or olive oil: possible role for paraoxonase-1 triacylglycerol lipase-like activity.

PubMed

Fuhrman, Bianca; Volkova, Nina; Aviram, Michael

2006-09-01

Postprandial triacylglycerols and oxidative stress responses are influenced by the type of fat consumed. We investigated the effect of individual unsaturated fatty acids or oils (fish, soy, or olive) on postprandial triglyceridemia response in association with serum resistance to oxidation and paraoxonase-1 (PON1) activity. Balb/C mice were supplemented with phosphate buffered saline (control), docosahexaenoic acid (omega-3), linoleic acid (omega-6), or oleic acid (omega-9; 500 microg/300 microL of phosphate buffered saline) and with fish, soy, or olive oil (300 microL); blood samples were collected 2 h after feeding. Serum triacylglycerol and oxidative stress responses increased after intake of all unsaturated fatty acids and oil supplements. However, ingestion of fish oil or its major fatty acid, docosahexaenoic acid, induced the most remarkable increase in postprandial serum triacylglycerols and in the susceptibility of serum to in vitro oxidation. Serum PON1 activity was decreased by 24% after fish oil ingestion. The increase in postprandial serum susceptibility to oxidation was lower after soy oil supplementation to PON1-transgenic mice in comparison with Balb/C mice, showing that PON1 attenuates the postprandial serum oxidative response. In parallel, in PON1-transgenic mice, a decreased postprandial triacylglycerol response was noted, suggesting PON1 involvement in triacylglycerol metabolism. PON1 exhibited a triacylglycerol lipase-like activity on chylomicrons. PON1 attenuates the postprandial oxidative stress response, and this could have resulted from PON1 lipase-like activity on chylomicron triacylglycerols.

Lithium Vanadium Oxide (Li 1.1V 3O 8) Coated with Amorphous Lithium Phosphorous Oxynitride (LiPON): Role of Material Morphology and Interfacial Structure on Resulting Electrochemistry

DOE PAGES

Zhang, Qing; Kercher, Andrew K.; Veith, Gabriel M.; ...

2017-05-16

In the present work, lithium vanadium oxide (Li 1.1V 3O 8) particles synthesized at two different temperatures were coated with an amorphous lithium phosphorous oxynitride (LiPON) film for the first time, and the effects of the LiPON coating on the electrochemistry of the Li 1.1V 3O 8 materials with different morphologies were systematically investigated by comparing uncoated Li 1.1V 3O 8 and Li 1.1V 3O 8 coated with LiPON of various thicknesses. Galvanostatic discharge-charge cycling revealed increased functional capacity for the LiPON-coated materials. Post-cycling electrochemical impedance spectroscopy showed that LiPON-coated Li 1.1V 3O 8 materials developed less interfacial resistance withmore » extended cycling, rationalized by vanadium migration into the LiPON coating seen by electron energy loss spectra. Post-mortem quantitative analysis of the anodes revealed more severe vanadium dissolution for the more irregularly shaped Li 1.1V 3O 8 materials with less LiPON coverage. Thus, this study highlights the specific benefits and limitations of LiPON coatings for stabilizing a moderate voltage Li 1.1V 3O 8 cathode material under extended cycling in liquid electrolyte, and describes a generally applicable approach for comprehensive characterization of a composite electroactive material which can be used to understand interfacial transport properties in other functional systems.« less

Phosphorylation of the Peptidoglycan Synthase PonA1 Governs the Rate of Polar Elongation in Mycobacteria

PubMed Central

Kieser, Karen J.; Baer, Christina E.; Barczak, Amy K.; Meniche, Xavier; Chao, Michael C.; Rego, E. Hesper; Sassetti, Christopher M.; Fortune, Sarah M.; Rubin, Eric J.

2015-01-01

Cell growth and division are required for the progression of bacterial infections. Most rod-shaped bacteria grow by inserting new cell wall along their mid-section. However, mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce new cell wall material at their poles. How mycobacteria control this different mode of growth is incompletely understood. Here we find that PonA1, a penicillin binding protein (PBP) capable of transglycosylation and transpeptidation of cell wall peptidoglycan (PG), is a major governor of polar growth in mycobacteria. PonA1 is required for growth of Mycobacterium smegmatis and is critical for M. tuberculosis during infection. In both cases, PonA1’s catalytic activities are both required for normal cell length, though loss of transglycosylase activity has a more pronounced effect than transpeptidation. Mutations that alter the amount or the activity of PonA1 result in abnormal formation of cell poles and changes in cell length. Moreover, altered PonA1 activity results in dramatic differences in antibiotic susceptibility, suggesting that a balance between the two enzymatic activities of PonA1 is critical for survival. We also find that phosphorylation of a cytoplasmic region of PonA1 is required for normal activity. Mutations in a critical phosphorylated residue affect transglycosylase activity and result in abnormal rates of cell elongation. Together, our data indicate that PonA1 is a central determinant of polar growth in mycobacteria, and its governance of cell elongation is required for robust cell fitness during both host-induced and antibiotic stress. PMID:26114871

Lithium Vanadium Oxide (Li 1.1V 3O 8) Coated with Amorphous Lithium Phosphorous Oxynitride (LiPON): Role of Material Morphology and Interfacial Structure on Resulting Electrochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Qing; Kercher, Andrew K.; Veith, Gabriel M.

In the present work, lithium vanadium oxide (Li 1.1V 3O 8) particles synthesized at two different temperatures were coated with an amorphous lithium phosphorous oxynitride (LiPON) film for the first time, and the effects of the LiPON coating on the electrochemistry of the Li 1.1V 3O 8 materials with different morphologies were systematically investigated by comparing uncoated Li 1.1V 3O 8 and Li 1.1V 3O 8 coated with LiPON of various thicknesses. Galvanostatic discharge-charge cycling revealed increased functional capacity for the LiPON-coated materials. Post-cycling electrochemical impedance spectroscopy showed that LiPON-coated Li 1.1V 3O 8 materials developed less interfacial resistance withmore » extended cycling, rationalized by vanadium migration into the LiPON coating seen by electron energy loss spectra. Post-mortem quantitative analysis of the anodes revealed more severe vanadium dissolution for the more irregularly shaped Li 1.1V 3O 8 materials with less LiPON coverage. Thus, this study highlights the specific benefits and limitations of LiPON coatings for stabilizing a moderate voltage Li 1.1V 3O 8 cathode material under extended cycling in liquid electrolyte, and describes a generally applicable approach for comprehensive characterization of a composite electroactive material which can be used to understand interfacial transport properties in other functional systems.« less

Paraoxonase responses to exercise and niacin therapy in men with metabolic syndrome.

PubMed

Taylor, James Kyle; Plaisance, Eric P; Mahurin, A Jack; Mestek, Michael L; Moncada-Jimenez, Jose; Grandjean, Peter W

2015-01-01

Our purpose was to characterize changes in paraoxonase 1 (PON1) activity and concentration after single aerobic exercise sessions conducted before and after 6 weeks of niacin therapy in men with metabolic syndrome (MetS). Twelve men with MetS expended 500 kcal by walking at 65% of VO2max before and after a 6-week regimen of niacin. Niacin doses were titrated by 500 mg/week from 500 to 1500 mg/day and maintained at 1500 mg/day for the last 4 weeks. Fasting blood samples were collected before and 24 hours after each exercise session and analyzed for PON1 activity, PON1 concentration, myeloperoxidase (MPO), apolipoprotein A1, oxidized low-density lipoprotein (oLDL), lipoprotein particle sizes and concentrations. PON1 activity, PON1 concentration, MPO, and oLDL were unaltered following the independent effects of exercise and niacin (P > 0.05 for all). High-density lipoprotein particle size decreased by 3% (P = 0.040) and concentrations of small very low-density lipoprotein increased (P = 0.016) following exercise. PON1 activity increased 6.1% (P = 0.037) and PON1 concentrations increased 11.3% (P = 0.015) with the combination of exercise and niacin. Exercise and niacin works synergistically to increase PON1 activity and concentration with little or no changes in lipoproteins or markers of lipid oxidation.

Association of Organophosphate Pesticide Exposure and Paraoxonase with Birth Outcome in Mexican-American Women

PubMed Central

Harley, Kim G.; Huen, Karen; Aguilar Schall, Raul; Holland, Nina T.; Bradman, Asa; Barr, Dana Boyd; Eskenazi, Brenda

2011-01-01

Background Epidemiologic studies suggest that maternal organophosphorus (OP) pesticide exposure is associated with poorer fetal growth, but findings are inconsistent. We explored whether paraoxonase (PON1), a key enzyme involved in detoxification of OPs, could be an effect modifier in this association. Methods The study population included 470 pregnant women enrolled in the CHAMACOS Study, a longitudinal cohort study of mothers and children living in an agricultural region of California. We analyzed urine samples collected from mothers twice during pregnancy for dialkyl phosphate (DAP) metabolites of OP pesticides. We analyzed maternal and fetal (cord) blood samples for PON1 genotype (PON1192 and PON1−108) and enzyme activity (paraoxonase and arylesterase). Infant birth weight, head circumference, and gestational age were obtained from medical records. Results Infants' PON1 genotype and activity were associated with birth outcome, but mothers' were not. Infants with the susceptible PON1−108TT genotype had shorter gestational age (β = −0.5 weeks, 95% Confidence Interval (CI): −0.9, 0.0) and smaller head circumference (β = −0.4 cm, 95% CI: −0.7, 0.0) than those with the PON1−108CC genotype. Infants' arylesterase and paraoxonase activity were positively associated with gestational age. There was some evidence of effect modification with DAPs: maternal DAP concentrations were associated with shorter gestational age only among infants of the susceptible PON1−108TT genotype (p-valueinteraction = 0.09). However, maternal DAP concentrations were associated with larger birth weight (p-valueinteraction = 0.06) and head circumference (p-valueinteraction<0.01) in infants with non-susceptible genotypes. Conclusions Infants whose PON1 genotype and enzyme activity levels suggested that they might be more susceptible to the effects of OP pesticide exposure had decreased fetal growth and length of gestation. PON1 may be another factor contributing to preterm or low birth weight birth. PMID:21904599

Addressing the link between paraoxonase-1 gene variants and the incidence of early onset myocardial infarction

PubMed Central

Hashad, Ingy M.; Abou-Aisha, Khaled; Abdel-Maksoud, Sahar M.; Gad, Mohamed Z.

2015-01-01

Introduction The enzyme paraoxonase-1 (PON1) represents an endogenous defense mechanism against vascular oxidative stress, thereby contributing to the prevention of atherosclerosis. Several polymorphisms have been reported in the PON1 gene, including Q192R. PON1 phenotype is commonly expressed as the paraoxonase/arylesterase ratio (PON/ARE). The major aim of this study was to investigate the association between PON1 Q192R polymorphism, PON1 phenotypes and the incidence of early-onset acute myocardial infarction (AMI) in Egyptians. Material and methods The study subjects consisted of 102 AMI patients and 72 age-matched healthy controls. Genotyping and enzyme activities were determined using PCR-RFLP and kinetic spectrophotometric assays, respectively. Results The genotype distribution for the PON1 gene was significantly different between AMI patients (QQ = 38.24%, QR = 49.02%, RR = 12.75%) and controls (QQ = 66.67%, QR = 25%, RR = 8.33%). Allele frequencies were also significantly different between patients (Q = 62.75%, R = 37.25%) and controls (Q = 79.17%, R = 20.83%). The genotypes QR and RR showed higher risk for AMI compared to the homozygous QQ (odds ratio (OR) = 3.231, p < 0.001). The average PON/ARE ratio in MI patients (1.187 ±0.1) did not differ significantly from controls (1.118 ±0.26). However, it showed a significant difference among different genotypes in both AMI patients (QQ = 0.91 ±0.11, QR = 1.09 ±0.11 and RR = 2.65 ±0.4) (p = 0.0002) and controls (QQ = 0.68 ±0.1, QR = 1.07 ±0.11 and RR = 4.89 ±2.84) (p < 0.0001). Conclusions PON1 192R allele represents an independent risk factor for early-onset AMI in Egyptians, and PON1 Q192R polymorphism modulates the paraoxonase phenotype. PMID:26170843

Paraoxonase 1 Q192R (PON1-192) polymorphism is associated with reduced lipid peroxidation in healthy young men on a low-carotenoid diet supplemented with tomato juice.

PubMed

Bub, Achim; Barth, Stephan W; Watzl, Bernhard; Briviba, Karlis; Rechkemmer, Gerhard

2005-03-01

The HDL-bound enzyme paraoxonase (PON) protects LDL from oxidation and may therefore attenuate the development of atherosclerosis. We examined the effect of tomato and carrot juice consumption on PON1 activity and lipid peroxidation in healthy young volunteers with different PON1-192 genotypes (Q/R substitution at position 192). In this randomized cross-over study twenty-two healthy, non-smoking men on a low-carotenoid diet received 330 ml/d tomato juice (37.0 mg lycopene, 1.6 mg beta-carotene) or carrot juice (27.1 mg beta-carotene, 13.1 mg alpha-carotene) for 2 weeks. Intervention periods were preceded by 2-week low-carotenoid intake. We determined the PON1-192 genotype by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) and measured ex vivo LDL oxidation (lag time), plasma malondialdehyde and PON1 activity at the beginning and end of each intervention period. At baseline, lag time was higher (P<0.05) in QQ (111 (sd 9) min) than in QR/RR subjects (101 (sd 8) min). Neither tomato nor carrot juice consumption had significant effects on PON1 activity. However, tomato juice consumption reduced (P<0.05) plasma malondialdehyde in QR/RR (Delta: -0.073 (sd 0.11) micromol/l) as compared to QQ subjects (Delta:+0.047 (sd 0.13) micromol/l). Carrot juice had no significant effect on malondialdehyde irrespective of the PON1-192 genotype. Male volunteers with the QR/RR genotype showed an increased lipid peroxidation at baseline. Although tomato and carrot juice fail to affect PON1 activity, tomato juice intake reduced lipid peroxidation in healthy volunteers carrying the R-allele of the PON1-192 genotype and could thus contribute to CVD risk reduction in these individuals.

Aerobic Training Modulates the Effects of Exercise-Induced Oxidative Stress on PON1 Activity: A Preliminary Study

PubMed Central

Otocka-Kmiecik, Aneta; Lewandowski, Marek; Szkudlarek, Urszula; Nowak, Dariusz; Orlowska-Majdak, Monika

2014-01-01

The aim of the study was to compare the effect of maximal exercise (ME) on paraoxonase (PON) and arylesterase (ARE) activity depending on lifestyle in respect to physical activity. The study was performed on 46 young men divided into two groups: sedentary (S) and physically active (PA). All participants performed ME on a treadmill. PON1 activities, FRAP, uric acid, bilirubin, TBARS, and lipid profile were determined in their blood before, at the bout of, and after ME. No significant differences in PON1 activities were found between S and PA subjects at baseline. Nearly all biochemicals increased at ME in both groups. Both PON and ARE activity increased at the bout of ME in PA subjects and only ARE activity in S subjects. ARE/HDL-C ratio increased at the bout of ME in PA and S subjects. The difference in PON1 activity response to ME between study groups may be a result of adaptation of PA subjects to regular physical activity. We suggest that PON1 activity may be a marker of antioxidant protection at ME and an indicator of adaptation to exercise. PMID:25379522

Difluorophosphoryl nitrene F2P(O)N: matrix isolation and unexpected rearrangement to F2PNO.

PubMed

Zeng, Xiaoqing; Beckers, Helmut; Willner, Helge; Neuhaus, Patrik; Grote, Dirk; Sander, Wolfram

2009-12-14

Triplet difluorophosphoryl nitrene F(2)P(O)N (X(3)A'') was generated on ArF excimer laser irradiation (lambda=193 nm) of F(2)P(O)N(3) in solid argon matrix at 16 K, and characterized by its matrix IR, UV/Vis, and EPR spectra, in combination with DFT and CBS-QB3 calculations. On visible light irradiation (lambda>420 nm) at 16 K F(2)P(O)N reacts with molecular nitrogen and some of the azide is regenerated. UV irradiation (lambda=255 nm) of F(2)P(O)N (X(3)A'') induced a Curtius-type rearrangement, but instead of a 1,3-fluorine shift, nitrogen migration to give F(2)PON is proposed to be the first step of the photoisomerization of F(2)P(O)N into F(2)PNO (difluoronitrosophosphine). Formation of novel F(2)PNO was confirmed with (15)N- and (18)O-enriched isotopomers by IR spectroscopy and DFT calculations. Theoretical calculations predict a rather long P-N bond of 1.922 A [B3LYP/6-311+G(3df)] and low bond-dissociation energy of 76.3 kJ mol(-1) (CBS-QB3) for F(2)PNO.

Aerobic training modulates the effects of exercise-induced oxidative stress on PON1 activity: a preliminary study.

PubMed

Otocka-Kmiecik, Aneta; Lewandowski, Marek; Szkudlarek, Urszula; Nowak, Dariusz; Orlowska-Majdak, Monika

2014-01-01

The aim of the study was to compare the effect of maximal exercise (ME) on paraoxonase (PON) and arylesterase (ARE) activity depending on lifestyle in respect to physical activity. The study was performed on 46 young men divided into two groups: sedentary (S) and physically active (PA). All participants performed ME on a treadmill. PON1 activities, FRAP, uric acid, bilirubin, TBARS, and lipid profile were determined in their blood before, at the bout of, and after ME. No significant differences in PON1 activities were found between S and PA subjects at baseline. Nearly all biochemicals increased at ME in both groups. Both PON and ARE activity increased at the bout of ME in PA subjects and only ARE activity in S subjects. ARE/HDL-C ratio increased at the bout of ME in PA and S subjects. The difference in PON1 activity response to ME between study groups may be a result of adaptation of PA subjects to regular physical activity. We suggest that PON1 activity may be a marker of antioxidant protection at ME and an indicator of adaptation to exercise.

Maintenance of Paraoxonase 2 Activity as a Strategy to Attenuate P. Aeruginosa Virulence

DTIC Science & Technology

2013-10-01

identify the putative PON2 interacting protein, our approach is to IP the ~300kD BS3 crosslinked complex with a GFP antibody , run the IP on an SDS-PAGE...Dianova) were used at 1:5000. HRP- conjugated secondary antibodies were from Cell Signaling. Stealth-PON2 and control siRNAs (Invitrogen) sequences and...the lactonase paraoxonase 2 (PON2) and induces many immunomodulatory effects in host cells. Because PON2 rapidly inactivates 3OC12, we hypothesized

Computational characterization of how the VX nerve agent binds human serum paraoxonase 1.

PubMed

Fairchild, Steven Z; Peterson, Matthew W; Hamza, Adel; Zhan, Chang-Guo; Cerasoli, Douglas M; Chang, Wenling E

2011-01-01

Human serum paraoxonase 1 (HuPON1) is an enzyme that can hydrolyze various chemical warfare nerve agents including VX. A previous study has suggested that increasing HuPON1's VX hydrolysis activity one to two orders of magnitude would make the enzyme an effective countermeasure for in vivo use against VX. This study helps facilitate further engineering of HuPON1 for enhanced VX-hydrolase activity by computationally characterizing HuPON1's tertiary structure and how HuPON1 binds VX. HuPON1's structure is first predicted through two homology modeling procedures. Docking is then performed using four separate methods, and the stability of each bound conformation is analyzed through molecular dynamics and solvated interaction energy calculations. The results show that VX's lone oxygen atom has a strong preference for forming a direct electrostatic interaction with HuPON1's active site calcium ion. Various HuPON1 residues are also detected that are in close proximity to VX and are therefore potential targets for future mutagenesis studies. These include E53, H115, N168, F222, N224, L240, D269, I291, F292, and V346. Additionally, D183 was found to have a predicted pKa near physiological pH. Given D183's location in HuPON1's active site, this residue could potentially act as a proton donor or accepter during hydrolysis. The results from the binding simulations also indicate that steered molecular dynamics can potentially be used to obtain accurate binding predictions even when starting with a closed conformation of a protein's binding or active site.

Monocyte-macrophage membrane possesses free radicals scavenging activity: stimulation by polyphenols or by paraoxonase 1 (PON1).

PubMed

Rosenblat, M; Elias, A; Volkova, N; Aviram, M

2013-04-01

In the current study, we analysed free radicals scavenging activity of monocytes-macrophages in the absence or presence of antioxidants such as polyphenols or paraoxonase 1 (PON1). THP-1 human monocytic cell line, murine J774A.1 macrophages, as well as human primary monocytes have the capability to scavenge free radicals, as measured by the 1-diphenyl-2-picryl-hydrazyl (DPPH) assay. This effect (which could be attributed to the cell's membrane) was cell number and incubation time dependent. Upon incubation of J774A.1 macrophages with acetylated LDL (Ac-LDL), with VLDL, or with the radical generator, AAPH, the cells' lipid peroxides content, and paraoxonase 2 (PON2) activity were significantly increased. While non-treated cells decreased DPPH absorbance by 65%, the Ac-LDL-, VLDL- or AAPH-treated cells, decreased it by only 33%, 30%, or 45%, respectively. We next analysed the effect of J774A.1 macrophage enrichment with antioxidants, such as polyphenols or PON1 on the cells' free radicals scavenging activity. Non-treated cells decreased DPPH absorbance by 50%, whereas vitamin E-, punicalagin- or PJ-treated cells significantly further decreased it, by 75%. Similarly, in PON1-treated cells DPPH absorbance was further decreased by 63%, in association with 23% increment in PON1 catalytic activity. In cells under oxidative stress [treated with AAPH-, or with oxidized LDL], PON1 activity was decreased by 31% or 40%, as compared to the activity observed in PON1 incubated with non-treated cells. We conclude that monocytes-macrophages possess free radicals scavenging activity, which is decreased under atherogenic conditions, and increased upon cell enrichment with potent antioxidants such as nutritional polyphenols, or PON1.

Association between Paraoxonase 1 (PON1) Polymorphisms and the Risk of Acute Coronary Syndrome in a North African Population

PubMed Central

Bounafaa, Abdelghani; Berrougui, Hicham; Ghalim, Noreddine; Nasser, Boubker; Bagri, Abdallah; Moujahid, Abderrahmane; Ikhlef, Souad; Camponova, Pamela; Yamoul, Najoua; Simo, Olivier Kamtchueng; Essamadi, Abdelkhalid; Khalil, Abdelouahed

2015-01-01

The purpose of the present study was to investigate the distribution of PON1 Q192R and L55M polymorphisms and activities in a North African population and to determine their association with cardiovascular complications. The prevalence of the QQ, QR, RR, LL, LM, and MM genotypes in the study population was 55.4%, 34.09%, 9.83%, 41.97%, 48.20%, and 9.83% respectively. The Q, R, L, and M alleles had a gene frequency of 0.755, 0.245, 0.67, and 0.33, respectively. The PON1 192 RR genotype was significantly more prevalent among ACS patients than among healthy subjects. There was a 4.33-fold increase in the risk of ACS in subjects presenting the PON1 192 RR genotype compared to those with the QQ genotype (OR=4.33; 95% CI=1.27–17.7). There was a significantly different distribution of PON1 L55M in the ACS patient groups (UA, STEMI, NSTEMI). Moreover, individuals presenting the PON1 55MM genotype present a higher risk for ACS than those with LL genotype (OR=3.69; 95% CI=1.61–11.80). Paraoxonase activities were significantly lower in coronary patients than in healthy subjects. The decrease in PON1 activity was inversely correlated with the number of concomitant risk factors for CVD (r=0.57, p<0.0001). The results of the present study suggested that the PON1 R and M alleles may play a role in the pathogenesis of cardiac ischemia in our North African population and that a decrease in PON1 activity may be a valuable marker for monitoring the development of the atherosclerosis process and the associated cardiovascular complications. PMID:26241956

Extra-virgin olive oil consumption reduces the age-related decrease in HDL and paraoxonase 1 anti-inflammatory activities.

PubMed

Loued, Soumaya; Berrougui, Hicham; Componova, Pamela; Ikhlef, Souad; Helal, Olfa; Khalil, Abdelouahed

2013-10-01

Paraoxonase 1 (PON1) is associated with HDL and modulates the antioxidant and anti-inflammatory role of HDL. The goals of the present study were to investigate the effect of ageing and the role of PON1 on the anti-inflammatory activity of HDL, and to determine whether extra-virgin olive oil (EVOO) consumption could improve the atheroprotective activity of HDL. HDL and PON1 were isolated from the plasma of ten young (Y-HDL and Y-PON1) and ten elderly (E-HDL and E-PON1) healthy volunteers before and after 12 weeks of EVOO consumption. Inflammation was assessed by measuring intracellular adhesion molecule 1 (ICAM-1) expression. THP-1 (human acute monocytic leukaemia cell line) monocyte chemotaxis was measured using a Boyden chamber. Oxidative damage to HDL was assessed by measuring conjugated diene formation and changes in electrophoretic migration. Y-HDL had more anti-inflammatory activity than E-HDL. The conjugated diene content and the electrophoretic mobility of E-HDL were higher than those of Y-HDL. Y-PON1 had significant anti-inflammatory activity, reducing ICAM-1 expression by 32·64 (SD 2·63)%, while E-PON1 had no significant effect. THP-1 chemotaxis measurements confirmed the ICAM-1 expression results. The 12 weeks of EVOO consumption significantly increased the anti-inflammatory activities of both HDL and PON1. The anti-inflammatory activity of HDL was modulated by PON1 and was lower in the elderly volunteers. EVOO consumption increased the anti-inflammatory effect of HDL and reduced the age-related decrease in anti-atherogenic activity.

A novel dynamic wavelength bandwidth allocation scheme over OFDMA PONs

NASA Astrophysics Data System (ADS)

Yan, Bo; Guo, Wei; Jin, Yaohui; Hu, Weisheng

2011-12-01

With rapid growth of Internet applications, supporting differentiated service and enlarging system capacity have been new tasks for next generation access system. In recent years, research in OFDMA Passive Optical Networks (PON) has experienced extraordinary development as for its large capacity and flexibility in scheduling. Although much work has been done to solve hardware layer obstacles for OFDMA PON, scheduling algorithm on OFDMA PON system is still under primary discussion. In order to support QoS service on OFDMA PON system, a novel dynamic wavelength bandwidth allocation (DWBA) algorithm is proposed in this paper. Per-stream QoS service is supported in this algorithm. Through simulation, we proved our bandwidth allocation algorithm performs better in bandwidth utilization and differentiate service support.

Experimental demonstration of the real-time online fault monitoring technique for chaos-based passive optical networks

NASA Astrophysics Data System (ADS)

Dou, Xinyu; Yin, Hongxi; Yue, Hehe; Jin, Yu; Shen, Jing; Li, Lin

2015-09-01

In this paper, a real-time online fault monitoring technique for chaos-based passive optical networks (PONs) is proposed and experimentally demonstrated. The fault monitoring is performed by the chaotic communication signal. The proof-of-concept experiments are demonstrated for two PON structures, i.e., wavelength-division-multiplexing (WDM) PON and Ethernet PON (EPON), respectively. For WDM PON, two monitoring approaches are investigated, one deploying a chaotic optical time domain reflectometry (OTDR) for each transmitter, and the other using only one tunable chaotic OTDR. The experimental results show that the faults at beyond 20 km from the OLT can be detected and located. The spatial resolution of the tunable chaotic OTDR is an order of magnitude of centimeter. Meanwhile, the monitoring process can operate in parallel with the chaotic optical secure communications. The proposed technique has benefits of real-time, online, precise fault location, and simple realization, which will significantly reduce the cost of operation, administration and maintenance (OAM) of PON.

Design and implementation of flexible TWDM-PON with PtP WDM overlay based on WSS for next-generation optical access networks

NASA Astrophysics Data System (ADS)

Wu, Bin; Yin, Hongxi; Qin, Jie; Liu, Chang; Liu, Anliang; Shao, Qi; Xu, Xiaoguang

2016-09-01

Aiming at the increasing demand of the diversification services and flexible bandwidth allocation of the future access networks, a flexible passive optical network (PON) scheme combining time and wavelength division multiplexing (TWDM) with point-to-point wavelength division multiplexing (PtP WDM) overlay is proposed for the next-generation optical access networks in this paper. A novel software-defined optical distribution network (ODN) structure is designed based on wavelength selective switches (WSS), which can implement wavelength and bandwidth dynamical allocations and suits for the bursty traffic. The experimental results reveal that the TWDM-PON can provide 40 Gb/s downstream and 10 Gb/s upstream data transmission, while the PtP WDM-PON can support 10 GHz point-to-point dedicated bandwidth as the overlay complement system. The wavelengths of the TWDM-PON and PtP WDM-PON are allocated dynamically based on WSS, which verifies the feasibility of the proposed structure.

Risk factors of patients with and without postoperative nausea (PON).

PubMed

Dienemann, Jacqueline; Hudgens, Amanda N; Martin, Dana; Jones, Holly; Hunt, Ronald; Blackwell, Richard; Norton, H James; Divine, George

2012-08-01

This purpose of this analysis was to study risk factors of postoperative nausea (PON) and their strength. Data were obtained during the screening phase of a controlled clinical trial of aromatherapy for PON. In a sample of 1151 postsurgical subjects, 301 (26.2%) reported PON. Significant risk factors identified in the order of odds ratios for nausea were female gender, gastrointestinal surgery, use of volatile anesthesia gases, history of PON, history of motion sickness, and use of opioids after surgery. Although still over 1.0, the risk factors of length of surgery over 1 hour and gynecologic surgery had the lowest odds ratios. Likelihood of nausea increased significantly with the number of significant risk factors (P<.0001). Administration of preventive antiemetic medication also increased with the number of significant risk factors (P<.0001). Among 301 subjects reporting nausea, 49 (16.28%) received preventive medication. Despite prevention efforts, PON remains a substantial side effect for many surgical patients. Copyright © 2012 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Human plasma paraoxonase 1 (PON1) arylesterase activity during aging: correlation with susceptibility of LDL oxidation.

PubMed

Mehdi, Mohammad Murtaza; Rizvi, Syed Ibrahim

2012-08-01

The role of free radicals has long been proposed as a cause for the aging process. Oxidative stress is considered a major factor for altering many physiological processes and enzymatic activities during aging and is also known to play a major role in the development of several age-dependent diseases. Paraoxonase 1 (PON1) is an anti-atherosclerotic enzyme that mainly prevents accumulation of lipoperoxides and inhibits the lipid oxidation in low-density lipoproteins (LDL). This study was undertaken to investigate the antioxidant behavior of PON1 by measuring its arylesterase activity. The susceptibility of LDL for oxidation and the radical scavenging activity of plasma were also measured during aging in humans. Arylesterase activity of PON1 was measured in plasma of human subjects between 20 and 81 years of age of both genders. The susceptibility of LDL for oxidation and radical scavenging activity were measured in plasma. Decrease in plasma arylesterase activity of PON1, increase in susceptibility of LDL for oxidation and decrease in plasma radical scavenging activity were observed as a function of human age. The study provides evidence of a relationship between PON1 activity, LDL oxidation and free radical scavenging activity of plasma. The present results emphasize the dependency of PON1 activity to prevailing oxidative stress during human aging. Our findings assume significance in view of the possible categorization of PON1 as a longevity gene. Copyright © 2012 IMSS. Published by Elsevier Inc. All rights reserved.

Paraoxonase 1 Phenotype and Mass in South Asian versus Caucasian Renal Transplant Recipients.

PubMed

Connelly, Philip W; Maguire, Graham F; Nash, Michelle M; Rapi, Lindita; Yan, Andrew T; Prasad, G V Ramesh

2012-01-01

South Asian renal transplant recipients have a higher incidence of cardiovascular disease compared with Caucasian renal transplant recipients. We carried out a study to determine whether paraoxonase 1, a novel biomarker for cardiovascular risk, was decreased in South Asian compared with Caucasian renal transplant recipients. Subjects were matched two to one on the basis of age and sex for a total of 129 subjects. Paraoxonase 1 was measured by mass, arylesterase activity, and two-substrate phenotype assay. Comparisons were made by using a matched design. The frequency of PON1 QQ, QR and RR phenotype was 56%, 37%, and 7% for Caucasian subjects versus 35%, 44%, and 21% for South Asian subjects (χ(2) = 7.72, P = 0.02). PON1 mass and arylesterase activity were not significantly different between South Asian and Caucasian subjects. PON1 mass was significantly associated with PON1 phenotype (P = 0.0001), HDL cholesterol (P = 0.009), LDL cholesterol (P = 0.02), and diabetes status (P < 0.05). Arylesterase activity was only associated with HDL cholesterol (P = 0.003). Thus the frequency of the PON1 RR phenotype was higher and that of the QQ phenotype was lower in South Asian versus Caucasian renal transplant recipients. However, ethnicity was not a significant factor as a determinant of PON1 mass or arylesterase activity, with or without analysis including PON1 phenotype. The two-substrate method for determining PON1 phenotype may be of value for future studies of cardiovascular complications in renal transplant recipients.

Methylmercury exposure, PON1 gene variants and serum paraoxonase activity in Eastern James Bay Cree adults.

PubMed

Drescher, Olivia; Dewailly, Eric; Diorio, Caroline; Ouellet, Nathalie; Sidi, Elhadji Anassour Laouan; Abdous, Belkacem; Valera, Beatriz; Ayotte, Pierre

2014-11-01

There is growing evidence that cardiovascular health can be affected by exposure to methylmercury (MeHg), by a mechanism involving oxidative stress. Paraoxonase 1 (PON1) is a high-density lipoprotein-bound enzyme that hydrolyzes toxic oxidized lipids and protects against cardiovascular diseases. Evidence from in vitro studies indicates that MeHg can inhibit PON1 activity but little is known regarding this effect in humans. We investigated whether increased blood mercury levels are associated with decreased serum PON1 activity in Cree people who are exposed to MeHg by fish consumption. We conducted a multi-community study of 881 Cree adults living in Eastern James Bay communities (Canada). Multivariate analyses considered sociodemographic, anthropometric, clinical, dietary and lifestyle variables and six PON1 gene variants (rs705379 (-108C/T), rs662 (Q192R), rs854560 (L55M), rs854572 (-909C/G), rs854571 (-832C/T) and rs705381 (-162C/T)). In a multiple regression model adjusted for all potential confounding factors and the rs854560 PON1 variant, a statistically significant MeHg*rs705379 interaction was observed. Blood mercury levels were inversely associated with serum PON1 activities in individual homozygous for the -108T allele (P=0.009). Our results suggest a gene-environment interaction between the rs705379 polymorphism and MeHg exposure on PON1 activity levels in this aboriginal population. This finding will need to be replicated in other population studies.

Morphometric study on dimensions of various parts of pons and comparison of data in accordance with age and sex of healthy people by MRI.

PubMed

Rajaei, Farzad; Salahshoor, Mohammad-Reza; Hashemi, Hassan-Jahani; Haghdoost-Yazdi, Hahsem; Pahlevan, Ali-Asghar

2009-12-01

The emergence of magnetic Resonance Imaging (MRI) technique has made it possible to answer many questions in the field of anatomy more precisely while observing different anatomic parts of living persons at different ages. This study was conducted to determine the dimensions of different parts of pons and also comparing the data in accordance with age and sex by MRI. The present study carried out on 300 healthy individuals referred to imaging center at Imam Reza hospital in the city of Kermanshah, Iran. The precondition for people to be included in the study was the approval made by in-house physician based on person's state of health and the lack of any pathological lesion in brain on the basis of images obtained by MRI. Following MRI procedure, the dimensions of target parts in pons were calculated by the MRI-associated measuring system and recorded along with the age and sex of the patients. Measurements were recorded in mm and based on selecting the largest height, width and length of the organ during the examination of all axial, sagittal, and T(1) coronal profiles. Data analysis was performed using t-student test and Pearson's correlation. The significance level was set at P=0.05. The mean size of different parts of pons recorded in mm was as follows: The height of tegmentum of pons in men and women were 21.10+/-1.99 and 20.35+/-1.95, respectively. The height of ventricle of pons was 24.96+/-1.45 in men and 23.72+/-1.41 in women. The length of pons in men was 21.40+/-1.55 and in women 21.10+/-1.28. The length of ventricle in men and women were 16.85+/-1.21 and 16.77+/-1.36, respectively. The length of tegmentum of pons was 4.57+/-0.50 in men and 4.40+/-0.58 in women. Lastly, the transverse length of the ventricle of pons was 27.30+/-1.68 in men and 26.52+/-1.63 in women. The values obtained for the transverse length, length of tegmentum of ventricle, height of ventricle and height of tegmentum in men were larger than those found for women. There were significant relationships between the transverse length, length of tegmentum of pons, height of ventricle of pons and the age in men. There was no significant relationship between dimension of pons and age in women.

Differentiation of muscarinic cholinergic receptor subtypes in human cortex and pons - Implications for anti-motion sickness therapy

NASA Technical Reports Server (NTRS)

Mccarthy, Bruce G.; Peroutka, Stephen J.

1988-01-01

Radioligand binding studies were used to analyze muscarinic cholinergic receptor subtypes in human cortex and pons. Muscarinic cholinergic receptors were labeled by H-3-quinuclidinyl benzilate (H-3-QNB). Scopolamine was equipotent in both brain regions and did not discriminate subtypes of H-3-QNB binding. By contrast, the M1 selective antagonist pirenzepine was approximately 33-fold more potent in human cortex than pons. Carbachol, a putative M2 selective agonist, was more than 100-fold more potent in human pons than cortex. These results demonstrate that the human pons contains a relatively large proportion of carbachol-sensitive muscarinic cholinergic receptors. Drugs targeted to this subpopulation of muscarinic cholinergic receptors may prove to be effective anti-motion sickness agents with less side effects than scopolamine.

Paraoxonase 1: a better atherosclerotic risk predictor than HDL in type 2 diabetes mellitus.

PubMed

Patra, Surajeet Kumar; Singh, Kamna; Singh, Ritu

2013-01-01

Type 2 diabetes mellitus is a state of glycative stress and oxidative stress. Lower level of serum PON 1 has been correlated to higher morbidity and mortality related to cardiovascular complications in type 2 diabetes mellitus. To estimate and compare the serum PON 1 levels in type 2 diabetes mellitus and controls and to predict which one is the better atherosclerotic risk predictor among HDL and PON 1 in T2DM patients. An observational analytical case-control study was conducted with a sample size of 30 in two groups like group I (30 cases of type 2 diabetes mellitus diagnosed by ADA 2010 criteria) and group II (30 age and sex matched controls). Human serum paroxonase 1 levels were measured by ELISA. Both HDL and PON 1 were negatively correlated with the various atherogenic indices (AIP, AC, CRI I, CRI II) but the strength of negative correlation is always greater for PON 1. In multiple linear regression analysis, we found that the regression coefficient (β) is always higher for PON 1 than for HDL while taking the atherogenic indices as outcome variable. PON 1 can be a better predictor than HDL for atherosclerotic risk in type 2 diabetes mellitus. Copyright © 2013 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Positive correlation of paraoxonase 1 (PON1) activity with serum insulin level and HOMA-IR in dementia. A possible advantageous role of PON1 in dementia development.

PubMed

Bednarska-Makaruk, Małgorzata; Graban, Ałła; Lipczyńska-Łojkowska, Wanda; Bochyńska, Anna; Rodo, Maria; Krzywkowski, Tomasz; Ryglewicz, Danuta; Wehr, Hanna

2013-01-15

Paraoxonase 1 (PON1) activity and metabolic syndrome traits were evaluated in 169 demented patients (81 recognized as AD, 32 as VaD, 56 as MD) and in 64 control individuals. Paraoxonase activity was determined spectrophotometrically using phenyloacetate as substrate. Metabolic syndrome was recognized according to AHA/NHLBI criteria. In the whole group with dementia significant positive correlation between PON1 activity/HDL cholesterol ratio (i.e. HDL corrected PON1 activity) and insulin level as well as HOMA IR index, was observed. The multivariate analysis showed that the PON1/HDL-C ratio was also significantly positively associated with the presence of metabolic syndrome (with insulin resistance as a major underlying trait) both in dementia and in control group. High insulin level and HOMA-IR are considered to be the traits of insulin resistance. It has however to be taken into account that they both could also depend on insulin production and release which, as was recently stated in cell experiments, are enhanced by PON1. The observed positive correlation suggests an advantageous role of the enzyme in metabolic syndrome influence on dementia development. Copyright © 2012 Elsevier B.V. All rights reserved.

Interfacial instability of amorphous LiPON against lithium: A combined Density Functional Theory and spectroscopic study

NASA Astrophysics Data System (ADS)

Sicolo, Sabrina; Fingerle, Mathias; Hausbrand, René; Albe, Karsten

2017-06-01

The chemical instability of the glassy solid electrolyte LiPON against metallic lithium and the occurrence of side reactions at their interface is investigated by combining a surface science approach and quantum-mechanical calculations. Using an evolutionary structure search followed by a melt-quenching protocol, a model for the disordered structure of LiPON is generated and put into contact with lithium. Even the static optimization of a simple model interface suggests that the diffusion of lithium into LiPON is driven by a considerable driving force that could easily take place under experimental conditions. Calculated reaction energies indicate that the reduction and decomposition of LiPON is thermodynamically favorable. By monitoring the evolution of the LiPON core levels as a function of lithium exposure, the disruption of the LiPON network alongside the occurrence of new phases is observed. The direct comparison between UV photoelectron spectroscopy measurements and calculated electronic densities of states for increasing stages of lithiation univocally identifies the new phases as Li2O, Li3P and Li3N. These products are stable against Li metal and form a passivation layer which shields the electrolyte from further decomposition while allowing for the diffusion of Li ions.

Cholinesterase and Paraoxonase (PON1) enzyme activities in Mexican-American Mothers and Children from an Agricultural Community

PubMed Central

Gonzalez, V.; Huen, K.; Venkat, S.; Pratt, K.; Xiang, P.; Harley, K.G.; Kogut, K.; Trujillo, C.M.; Bradman, A.; Eskenazi, B.; Holland, N.T.

2014-01-01

Exposure to organophosphate and carbamate pesticides can lead to neurotoxic effects through inhibition of cholinesterase enzymes. The paraoxonase (PON1) enzyme can detoxify oxon derivatives of some organophosphates. Lower PON1, acetylcholinesterase, and butyrylcholinesterase activities have been reported in newborns relative to adults, suggesting increased susceptibility to organophosphate exposure in young children. We determined PON1, acetylcholinesterase, and butyrylcholinesterase activities in Mexican-American mothers and their 9-year-old children (n=202 pairs) living in an agricultural community in California. We used paired t-tests to compare enzymatic activities among mothers and their children and analysis of variance to determine which factors are associated with enzyme activities. Substrate-specific PON1 activities were slightly lower in children than their mothers; however, these differences were not statistically significant. We observed significantly lower acetylcholinesterase but higher butyrylcholinesterase levels in children compared to their mothers. Mean butyrylcholinesterase levels were strongly associated with child obesity status (BMI Z scores >95%). We observed highly significant correlations among mother-child pairs for each of the enzymatic activities analyzed; however, PON1 activities did not correlate with acetylcholinesterase or butyrylcholinesterase activities. Our findings suggest that by age nine, PON1 activities approach adult levels and host factors including sex and obesity may affect key enzymes involved in pesticide metabolism. PMID:22760442

Relationship Between Paraoxonase-1 and Butyrylcholinesterase Activities and Nutritional Status in Mexican Children.

PubMed

Ramírez-Jiménez, Rocío; Martínez-Salazar, María Fernanda; Almenares-López, Damianys; Yáñez-Estrada, Leticia; Monroy-Noyola, Antonio

2018-03-01

The enzymes butyrylcholinesterase (BuChE) and paraoxonase-1 (PON1) are the primary bioscavenging enzymes in serum and exhibit antioxidant and anti-inflammatory activities. PON1 has been associated with diseases caused by high oxidative stress, whereas BuChE appears to be involved in the pathophysiology of the metabolic syndrome and related disorders. It has been suggested that children from rural communities in Mexico may have a predisposition to develop obesity or type 2 diabetes during adolescence or adulthood. The objective of this study was to determine whether associations exist between the paraoxonase (PONase)/arylesterase (AREase) activity of PON1, its PON1-Q192R and PON1-L55M polymorphisms, and BuChE activity with the nutritional status and lipid profiles in a group of children from rural communities in Mexico. A group of 97 boys and girls from a rural community in Mexico were assessed for body mass index, the enzymatic activities of BuChE, PONase, and AREase were measured in serum, and their lipid profiles were determined. Genetic polymorphisms of PON1-L55M and PON1-Q192R were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The children were classified into four groups: thinness, normal weight, overweight, and obese. Of the children studied, 34.4% were overweight and obese. The mean age of the participants was 9.5 years (standard deviation = 1.8). The L allele of the PON1-L55M genotype was the most frequent (83.3%), and the R allele of the PON1-Q192R genotype was the most frequent (61.8%). Overweight and obese children had higher values of BuChE, total cholesterol, triglycerides (TG), and lower high-density lipoprotein (HDL-C) values than children with thinness or normal weight (P = 0.028, P = 0.019, P = 0.004, P = 0.069 and P = 0.021, respectively). The levels of AREase and PONase and the prevalence of PON1-L55M and PON1-Q192R genotypes were similar between groups (P = 0.484 and P = 0.380, respectively). This study establishes a positive association of BuChE activity with nutritional status and serum TG.

Flexible and evolutionary optical access networks

NASA Astrophysics Data System (ADS)

Hsueh, Yu-Li

Passive optical networks (PONs) are promising solutions that will open the first-mile bottleneck. Current PONs employ time division multiplexing (TDM) to share bandwidth among users, leading to low cost but limited capacity. In the future, wavelength division multiplexing (WDM) technologies will be deployed to achieve high performance. This dissertation describes several advanced technologies to enhance PON systems. A spectral shaping line coding scheme is developed to allow a simple and cost-effective overlay of high data-rate services in existing PONs, leaving field-deployed fibers and existing services untouched. Spectral shapes of coded signals can be manipulated to adapt to different systems. For a specific tolerable interference level, the optimal line code can be found which maximizes the data throughput. Experiments are conducted to demonstrate and compare several optimized line codes. A novel PON employing dynamic wavelength allocation to provide bandwidth sharing across multiple physical PONs is designed and experimentally demonstrated. Tunable lasers, arrayed waveguide gratings, and coarse/fine filtering combine to create a flexible optical access solution. The network's excellent scalability can bridge the gap between conventional TDM PONs and WDM PONs. Scheduling algorithms with quality of service support are also investigated. Simulation results show that the proposed architecture exhibits significant performance gain over conventional PON systems. Streaming video transmission is demonstrated on the prototype experimental testbed. The powerful architecture is a promising candidate for next-generation optical access networks. A new CDR circuit for receiving the bursty traffic in PONs is designed and analyzed. It detects data transition edges upon arrival of the data burst and quickly selects the best clock phase by a control logic circuit. Then, an analog delay-locked loop (DLL) keeps track of data transitions and removes phase errors throughout the burst. The combination of the fast phase detection mechanism and a feedback loop based on DLL allows both fast response and manageable jitter performance in the burst-mode application. A new efficient numerical algorithm is developed to analyze holey optical fibers. The algorithm has been verified against experimental data, and is exploited to design holey optical fibers optimized for the discrete Raman amplification.

Simultaneous aerosol mass spectrometry and chemical ionisation mass spectrometry measurements during a biomass burning event in the UK: insights into nitrate chemistry

NASA Astrophysics Data System (ADS)

Reyes-Villegas, Ernesto; Priestley, Michael; Ting, Yu-Chieh; Haslett, Sophie; Bannan, Thomas; Le Breton, Michael; Williams, Paul I.; Bacak, Asan; Flynn, Michael J.; Coe, Hugh; Percival, Carl; Allan, James D.

2018-03-01

Over the past decade, there has been an increasing interest in short-term events that negatively affect air quality such as bonfires and fireworks. High aerosol and gas concentrations generated from public bonfires or fireworks were measured in order to understand the night-time chemical processes and their atmospheric implications. Nitrogen chemistry was observed during Bonfire Night with nitrogen containing compounds in both gas and aerosol phases and further N2O5 and ClNO2 concentrations, which depleted early next morning due to photolysis of NO3 radicals and ceasing production. Particulate organic oxides of nitrogen (PONs) concentrations of 2.8 µg m-3 were estimated using the m / z 46 : 30 ratios from aerosol mass spectrometer (AMS) measurements, according to previously published methods. Multilinear engine 2 (ME-2) source apportionment was performed to determine organic aerosol (OA) concentrations from different sources after modifying the fragmentation table and it was possible to identify two PON factors representing primary (pPON_ME2) and secondary (sPON_ME2) contributions. A slight improvement in the agreement between the source apportionment of the AMS and a collocated AE-31 Aethalometer was observed after modifying the prescribed fragmentation in the AMS organic spectrum (the fragmentation table) to determine PON sources, which resulted in an r2 = 0.894 between biomass burning organic aerosol (BBOA) and babs_470wb compared to an r2 = 0.861 obtained without the modification. Correlations between OA sources and measurements made using time-of-flight chemical ionisation mass spectrometry with an iodide adduct ion were performed in order to determine possible gas tracers to be used in future ME-2 analyses to constrain solutions. During Bonfire Night, strong correlations (r2) were observed between BBOA and methacrylic acid (0.92), acrylic acid (0.90), nitrous acid (0.86), propionic acid, (0.85) and hydrogen cyanide (0.76). A series of oxygenated species and chlorine compounds showed good correlations with sPON_ME2 and the low volatility oxygenated organic aerosol (LVOOA) factor during Bonfire Night and an event with low pollutant concentrations. Further analysis of pPON_ME2 and sPON_ME2 was performed in order to determine whether these PON sources absorb light near the UV region using an Aethalometer. This hypothesis was tested by doing multilinear regressions between babs_470wb and BBOA, sPON_ME2 and pPON_ME2. Our results suggest that sPON_ME2 does not absorb light at 470 nm, while pPON_ME2 and LVOOA do absorb light at 470 nm. This may inform black carbon (BC) source apportionment studies from Aethalometer measurements, through investigation of the brown carbon contribution to babs_470wb.

Interleukin-6 upregulates paraoxonase 1 gene expression via an AKT/NF-κB-dependent pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Chi-Chih; Hsueh, Chi-Mei; Chen, Chiu-Yuan

2013-07-19

Highlights: •IL-6 could induce PON1 gene expression. •IL-6 increased NF-κB protein expression and NF-κB-p50 and -p65 subunits nuclear translocation. •IL-6-induced PON1 up-regulation was through an AKT/NF-κB pathway. -- Abstract: The aim of this study is to investigate the relationship between paraoxonase 1 (PON1) and atherosclerosis-related inflammation. In this study, human hepatoma HepG2 cell line was used as a hepatocyte model to examine the effects of the pro-inflammatory cytokines on PON1 expression. The results showed that IL-6, but not TNF-α and IL-1β, significantly increased both the function and protein level of PON1; data from real-time RT-PCR analysis revealed that the IL-6-inducedmore » PON1 expression occurred at the transcriptional level. Increase of IκB kinase activity and IκB phosphorylation, and reduction of IκB protein level were also observed in IL-6-treated HepG2 cells compared with untreated culture. This event was accompanied by increase of NF-κB-p50 and -p65 nuclear translocation. Moreover, treatment with IL-6 augmented the DNA binding activity of NF-κB. Furthermore, pharmacological inhibition of NF-κB activation by PDTC and BAY 11-7082, markedly suppressed the IL-6-mediated PON1 expression. In addition, IL-6 increased the levels of phosphorylated protein kinase B (PKB, AKT). An AKT inhibitor LY294002 effectively suppressed IKK/IκB/NF-κB signaling and PON1 gene expression induced by IL-6. Our findings demonstrate that IL-6 upregulates PON1 gene expression through an AKT/NF-κB signaling axis in human hepatocyte-derived HepG2 cell line.« less

Activity and determinants of cholinesterases and paraoxonase-1 in blood of workers exposed to non-cholinesterase inhibiting pesticides.

PubMed

Lozano-Paniagua, David; Gómez-Martín, Antonio; Gil, Fernando; Parrón, Tesifón; Alarcón, Raquel; Requena, Mar; Lacasaña, Marina; Hernández, Antonio F

2016-11-25

Pesticide exposure has been associated with different adverse health effects which may be modulated to some extent by paraoxonase-1 (PON1) activity and genetic polymorphisms. This study assessed seasonal variations in PON1 activity (using paraoxon -POase-, phenylacetate -AREase-, diazoxon -DZOase- and dihydrocoumarin -DHCase- as substrates), erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (using butyrylthiocholine -BuChE- and benzoylcholine -BeChE- as substrates. The study population consisted of intensive agriculture workers regularly exposed to pesticides other than organophosphates and non-exposed controls from Almería (Southeastern Spain). The effect of common genetic polymorphisms of PON1 and BCHE on paraoxonase-1 and cholinesterase activities toward different substrates was also assessed. Linear mixed models were used to compare esterase activities in agricultural workers and control subjects over the two study periods (high and low exposure to pesticides). The significant decrease in AChE and increase in BuChE and BeChE activities observed in workers with respect to control subjects was attributed to pesticide exposure. Workers also had higher levels of AREase, DZOase and, to a lesser extent, of POase, but showed decreased DHCase activity. While PON1 Q192R and PON1 -108C/T gene polymorphisms were significantly associated with all PON1 activities, PON1 L55M showed a significant association with AREase, DZOase and DHCase. BCHE-K (Karlow variant) was significantly associated with lower BeChE activity (but not with BuChE) and BCHE-A (atypical variant) showed no significant association with any cholinesterase activity. These findings suggest that increased PON1, BuChE and BeChE activities in exposed workers might result from an adaptive response against pesticide exposure to compensate for adverse effects at the biochemical level. This response appears to be modulated by PON1 and BCHE gene polymorphisms. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Renal cortical thickness and PON1 activity both decrease in chronic renal failure.

PubMed

Ak, Gülçin; Ozgönül, Mert; Sözmen, Eser Y; Aslan, S Leyla; Sözmen, Bülent

2002-01-01

Chronic renal failure (CRF) is associated with a tendency to atherosclerosis due to the enhanced oxidative stress and insufficient antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT) and paraoxonase (PON 1), together with abnormalities in lipid parameters. We determined the in vitro susceptibility of low-density lipoprotein (LDL) to oxidation and PON1 activities in patients with chronic renal insufficiency to see how PON1 affected the progression of the disease and whether hemodialysis influenced these parameters. Thirty-seven patients (21 men, 16 women, mean age 43.9 +/- 16) with CRF were included, 23 were receiving hemodialysis treatment. Exclusion criteria were diabetes mellitus and acute coronary disease. Eighteen healthy subjects (9 men and 9 women, mean age 39.9 +/- 10.5) volunteered to participate as controls. All patients were evaluated by renal ultrasound (USG) and two-dimensional echography, and their lipid profiles, PON1 activity, basal and Cu-induced LDL oxidation were determined. PON1 activities of patients were lower than controls (14.4 +/- 11 vs 30.9 +/- 19 U/L, p < 0.05) while basal ox-LDL levels determined by the thiobarbituric acid reactive substances (TBARS) method were higher (0.6 +/- 0.4 vs 0.4+/- 0.2 nmol/mg LDL protein, p<0.01). There was no significant difference between the groups treated with hemodialysis or not. There was a positive correlation between renal cortical thickness and HDL levels (r=0.47, p=0.006) and PON1 activity (r=0.45, p=0.01). Our data showed that HDL cholesterol levels and PON1 activities were both lower in patients, indicating depletion of the protective antioxidant capacity. PON1 activities and phenotypes were no different in patients with coronary disease and others so it does not appear to be a significant indicator of coronary artery disease in patients with CRF.

A TTC upgrade proposal using bidirectional 10G-PON FTTH technology

NASA Astrophysics Data System (ADS)

Kolotouros, D. M.; Baron, S.; Soos, C.; Vasey, F.

2015-04-01

A new generation FPGA-based Timing-Trigger and Control (TTC) system based on emerging Passive Optical Network (PON) technology is being proposed to replace the existing off-detector TTC system used by the LHC experiments. High split ratio, dynamic software partitioning, low and deterministic latency, as well as low jitter are required. Exploiting the latest available technologies allows delivering higher capacity together with bidirectionality, a feature absent from the legacy TTC system. This article focuses on the features and capabilities of the latest TTC-PON prototype based on 10G-PON FTTH components along with some metrics characterizing its performance.

Can target-to-pons ratio be used as a reliable method for the analysis of [11C]PIB brain scans?

PubMed

Edison, P; Hinz, R; Ramlackhansingh, A; Thomas, J; Gelosa, G; Archer, H A; Turkheimer, F E; Brooks, D J

2012-04-15

(11)C]PIB is the most widely used PET imaging marker for amyloid in dementia studies. In the majority of studies the cerebellum has been used as a reference region. However, cerebellar amyloid may be present in genetic Alzheimer's (AD), cerebral amyloid angiopathy and prion diseases. Therefore, we investigated whether the pons could be used as an alternative reference region for the analysis of [(11)C]PIB binding in AD. The aims of the study were to: 1) Evaluate the pons as a reference region using arterial plasma input function and Logan graphical analysis of binding. 2) Assess the power of target-to-pons ratios to discriminate controls from AD subjects. 3) Determine the test-retest reliability in AD subjects. 4) Demonstrate the application of target-to-pons ratio in subjects with elevated cerebellar [(11)C]PIB binding. 12 sporadic AD subjects aged 65 ± 4.5 yrs with a mean MMSE 21.4 ± 4 and 10 age-matched control subjects had [(11)C]PIB PET with arterial blood sampling. Three additional subjects (two subjects with pre-symptomatic presenilin-1 mutation carriers and one probable familial AD) were also studied. Object maps were created by segmenting individual MRIs and spatially transforming the gray matter images into standard stereotaxic MNI space and then superimposing a probabilistic atlas. Cortical [(11)C]PIB binding was assessed with an ROI (region of interest) analysis. Parametric maps of the volume of distribution (V(T)) were generated with Logan analysis. Additionally, parametric maps of the 60-90 min target-to-cerebellar ratio (RATIO(CER)) and the 60-90 min target-to-pons ratio (RATIO(PONS)) were computed. All three approaches were able to differentiate AD from controls (p<0.0001, nonparametric Wilcoxon rank sum test) in the target regions with RATIO(CER) and RATIO(PONS) differences higher than V(T) with use of an arterial input function. All methods had a good reproducibility (intraclass correlation coefficient>0.83); RATIO(CER) performed best closely followed by RATIO(PONS). The two subjects with presenilin-1 mutations and the probable familial AD case showed no significant differences in cortical binding using RATIO(CER), but the RATIO(PONS) approach revealed higher [(11)C]PIB binding in cortex and cerebellum. This study established 60-90 min target-to-pons RATIOs as a reliable method of analysis in [(11)C]PIB PET studies where cerebellum is not an appropriate reference region. Copyright © 2012 Elsevier Inc. All rights reserved.

Paraoxonase 1 (PON1) Q192R genotypes and their interaction with smoking strongly increase atherogenicity and the Framingham risk score.

PubMed

Souza-Nogueira, Andre de; Camargo, Alissana Ester; Remondi, Felipe Assan; Paoliello, Monica Maria Bastos; Richter, Rebecca J; Furlong, Clement E; Barbosa, Decio Sabbatini; Maes, Michael; Moreira, Estefania Gastaldello

2016-10-01

Paraoxonase 1 (PON1) polymorphisms are associated with an increased susceptibility to cardiovascular disease. PON1 Q192R polymorphism (rs662) partially determine PON1 hydrolytic activity and protect against oxidation of LDL and HDL. This study aimed to delineate the association of PON1 status (functional 192 genotype and plasma activity levels) and atherogenicity in urbans residents aged 40 years or more. Anthropometric data, lipid profiles, the atherogenic index of the plasma (AIP) and Framingham score risk were measured. Three kinetic assays were conducted to assay PON1 status using phenylacetate and 4-(chloromethyl)phenyl acetate as substrates. Smoking per se did not significantly impact the AIP but the interaction PON1 genotype by smoking significantly increased the AIP. In subjects with the RR genotype smoking increased the AIP index from (estimated mean ± SEM) -0.038 ± 0.039 to 0.224 ± 0.094. The QR genotype increased the Framingham risk index by around 1.3 points. Smoking by RR genotype carriers significantly increased the Framingham risk score (17.23 ± 2.04) as compared to smoking (13.00 ± 1.06) and non-smoking (7.79 ± 0.70) by QQ+QR genotype carriers. The interaction RR genotype by smoking was a more important predictor (odds ratio = 7.90) of an increased Framingham risk score (> 20) than smoking per se (odds ratio = 2.73). The interaction smoking by RR genotype carriers significantly increased triglycerides and lowered HDL cholesterol. Smoking per se has no (AIP) or a mild (Framingham risk score) effect on atherogenicity, while the interaction smoking by PON1 RR genotype has a clinically highly significant impact on atherogenicity.

Paraoxonase 1 activity and level of antibodies directed against oxidized low density lipoproteins in a group of an elderly population in Poland - PolSenior study.

PubMed

Bednarska-Makaruk, Małgorzata; Rodo, Maria; Szirkowiec, Walentyna; Mossakowska, Małgorzata; Puzianowska-Kuźnicka, Monika; Skalska, Anna; Zdrojewski, Tomasz; Ryglewicz, Danuta; Wehr, Hanna

2015-01-01

The aim of this study was to assess two factors influencing the amount of oxidized LDL-paraoxonase 1 (PON1) activity and the level of anti-oxidized LDL antibodies (anti-ox LDL) in a large group of elderly individuals in Poland. The effects of cognitive status, hypertension and metabolic syndrome and of selected serum lipids and inflammation indicators on PON1 activity and anti-ox LDL level were also examined. The investigated population consisted of 3154 individuals aged 65 and more - participants of the population-based PolSenior project. PON1 arylesterase activity was determined spectrophotometrically, anti-ox-LDL antibodies using ELISA method. PON1 activity significantly decreased with advancing age, was lower in males than in females and decreased in persons with impaired cognition. Individuals with hypertension and high lipid levels showed higher PON1 activity. Lower PON1 activity was related to higher level of inflammation indicators - hsCRP and IL-6. The significant association of PON1 activity with age, HDL-C, LDL-C, sex and IL-6 was confirmed in multivariate analysis. Anti-ox LDL antibodies level was significantly higher in the two oldest subgroups of males. It was significantly lower in males than in females. It was decreased in persons with higher serum triglycerides. No relationship of anti-ox LDL level with cognition, hypertension, metabolic syndrome, inflammation indicators and serum lipid levels was observed. In some persons very high levels of anti-ox LDL were stated, most frequently in the oldest persons, particularly in men. Both investigated antioxidant factors - PON1 activity and anti-ox LDL level, could play an important role in aging. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Building an Energy-efficient Uplink and Downlink Delay Aware TDM-PON System

NASA Astrophysics Data System (ADS)

Newaz, S. H. Shah; Jang, Min Seok; Alaelddin, Fuad Yousif Mohammed; Lee, Gyu Myoung; Choi, Jun Kyun

2016-05-01

With the increasing concern over the energy expenditure due to rapid ICT expansion and growth of Internet traffic volume, there is a growing trend towards developing energy-efficient ICT solutions. Passive Optical Network (PON), which is regarded as a key enabler to facilitate high speed broadband connection to individual subscribers, is considered as one of the energy-efficient access network technologies. However, an immense amount of research effort can be noticed in academia and industries to make PON more energy-efficient. In this paper, we aim at improving energy saving performance of Time Division Multiplexing (TDM)-PON, which is the most widely deployed PON technology throughout the world. A commonly used approach to make TDM-PON energy-efficient is to use sleep mode in Optical Network Units (ONUs), which are the customer premises equipment of a TDM-PON system. However, there is a strong trade-off relationship between traffic delay performance of an ONU and its energy saving (the longer the sleep interval length of an ONU, the lower its energy consumption, but the higher the traffic delay, and vice versa). In this paper, we propose an Energy-efficient Uplink and Downlink Delay Aware (EUDDA) scheme for TDM-PON system. The prime object of EUDDA is to meet both downlink and uplink traffic delay requirement while maximizing energy saving performance of ONUs as much as possible. In EUDDA, traffic delay requirement is given more priority over energy saving. Even so, it still can improve energy saving of ONUs noticeably. We evaluate performance of EUDDA in front of two existing solutions in terms of traffic delay, jitter, and ONU energy consumption. The performance results show that EUDDA significantly outperforms the other existing solutions.

Connection anonymity analysis in coded-WDM PONs

NASA Astrophysics Data System (ADS)

Sue, Chuan-Ching

2008-04-01

A coded wavelength division multiplexing passive optical network (WDM PON) is presented for fiber to the home (FTTH) systems to protect against eavesdropping. The proposed scheme applies spectral amplitude coding (SAC) with a unipolar maximal-length sequence (M-sequence) code matrix to generate a specific signature address (coding) and to retrieve its matching address codeword (decoding) by exploiting the cyclic properties inherent in array waveguide grating (AWG) routers. In addition to ensuring the confidentiality of user data, the proposed coded-WDM scheme is also a suitable candidate for the physical layer with connection anonymity. Under the assumption that the eavesdropper applies a photo-detection strategy, it is shown that the coded WDM PON outperforms the conventional TDM PON and WDM PON schemes in terms of a higher degree of connection anonymity. Additionally, the proposed scheme allows the system operator to partition the optical network units (ONUs) into appropriate groups so as to achieve a better degree of anonymity.

All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

PubMed

Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

2011-11-21

We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible. © 2011 Optical Society of America

Power Budget Analysis of Colorless Hybrid WDM/TDM-PON Scheme Using Downstream DPSK and Re-modulated Upstream OOK Data Signals

NASA Astrophysics Data System (ADS)

Khan, Yousaf; Afridi, Muhammad Idrees; Khan, Ahmed Mudassir; Rehman, Waheed Ur; Khan, Jahanzeb

2014-09-01

Hybrid wavelength-division multiplexed/time-division multiplexed passive optical access networks (WDM/TDM-PONs) combine the advance features of both WDM and TDM PONs to provide a cost-effective access network solution. We demonstrate and analyze the transmission performances and power budget issues of a colorless hybrid WDM/TDM-PON scheme. A 10-Gb/s downstream differential phase shift keying (DPSK) and remodulated upstream on/off keying (OOK) data signals are transmitted over 25 km standard single mode fiber. Simulation results show error free transmission having adequate power margins in both downstream and upstream transmission, which prove the applicability of the proposed scheme to future passive optical access networks. The power budget confines both the PON splitting ratio and the distance between the Optical Line Terminal (OLT) and Optical Network Unit (ONU).

Monitoring technique for multiple power splitter-passive optical networks using a tunable OTDR and FBGs

NASA Astrophysics Data System (ADS)

Hann, Swook; Kim, Dong-Hwan; Park, Chang-Soo

2006-04-01

A monitoring technique for multiple power splitter-passive optical networks (PS-PON) is presented. The technique is based on the remote sensing of fiber Bragg grating (FBG) using a tunable OTDR. To monitor the multiple PS-PON, the FBG can be used for a wavelength dependent reflective reference on each branch end of the PS. The FBG helps discern an individual event of the multiple PS-PON for the monitoring in collaborate with information of Rayleigh backscattered power. The multiple PS-PON can be analyzed by the monitoring method at the central office under 10-Gbit/s in-service.

Cost-effective and monitoring-active technique for TDM-passive optical networks

NASA Astrophysics Data System (ADS)

Chi, Chang-Chia; Lin, Hong-Mao; Tarn, Chen-Wen; Lin, Huang-Liang

2014-08-01

A reliable, detection-active and cost-effective method which employs the hello and heartbeat signals for branched node distinguishing to monitor fiber fault in any branch of distribution fibers of a time division multiplexing passive optical network (TDM-PON) is proposed. With this method, the material cost of building an optical network monitor system for a TDM-PON with 168 ONUs and the time of identifying a multiple branch faults is significantly reduced in a TDM-PON system of any scale. A fault location in a 1 × 32 TDM-PON system using this method to identify the fault branch is demonstrated.

Chaos-based CAZAC scheme for secure transmission in OFDM-PON

NASA Astrophysics Data System (ADS)

Fu, Xiaosong; Bi, Meihua; Zhou, Xuefang; Yang, Guowei; Lu, Yang; Hu, Miao

2018-01-01

To effectively resist malicious eavesdropping and performance deterioration, a novel chaos-based secure transmission scheme is proposed to enhance the physical layer security and reduce peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing passive optical network (OFDM-PON). By the randomly extracting operation of common CAZAC values, the specially-designed constant amplitude zero autocorrelation (CAZAC) is created for system encryption and PAPR reduction enhancing the transmission security. This method is verified in {10-Gb/s encrypted OFDM-PON with 20-km fiber transmission. Results show that, compared to common OFDM-PON, our scheme achieves {3-dB PAPR reduction and {1-dB receiver sensitivity improvement.

Time resolved impedance spectroscopy analysis of lithium phosphorous oxynitride - LiPON layers under mechanical stress

NASA Astrophysics Data System (ADS)

Glenneberg, Jens; Bardenhagen, Ingo; Langer, Frederieke; Busse, Matthias; Kun, Robert

2017-08-01

In this paper we present investigations on the morphological and electrochemical changes of lithium phosphorous oxynitride (LiPON) under mechanically bent conditions. Therefore, two types of electrochemical cells with LiPON thin films were prepared by physical vapor deposition. First, symmetrical cells with two blocking electrodes (Cu/LiPON/Cu) were fabricated. Second, to simulate a more application-related scenario cells with one blocking and one non-blocking electrode (Cu/LiPON/Li/Cu) were analyzed. In order to investigate mechanical distortion induced transport property changes in LiPON layers the cells were deposited on a flexible polyimide substrate. Morphology of the as-prepared samples and deviations from the initial state after applying external stress by bending the cells over different radii were investigated by Focused Ion Beam- Scanning Electron Microscopy (FIB-SEM) cross-section and surface images. Mechanical stress induced changes in the impedance were evaluated by time-resolved electrochemical impedance spectroscopy (EIS). Due to the formation of a stable, ion-conducting solid electrolyte interphase (SEI), cells with lithium show decreased impedance values. Furthermore, applying mechanical stress to the cells results in a further reduction of the electrolyte resistance. These results are supported by finite element analysis (FEA) simulations.

Highly functionalized organic nitrates in the southeast United States: Contribution to secondary organic aerosol and reactive nitrogen budgets

PubMed Central

Mohr, Claudia; Lopez-Hilfiker, Felipe D.; Lutz, Anna; Hallquist, Mattias; Lee, Lance; Romer, Paul; Cohen, Ronald C.; Iyer, Siddharth; Kurtén, Theo; Hu, Weiwei; Day, Douglas A.; Campuzano-Jost, Pedro; Jimenez, Jose L.; Xu, Lu; Ng, Nga Lee; Guo, Hongyu; Weber, Rodney J.; Wild, Robert J.; Brown, Steven S.; Koss, Abigail; de Gouw, Joost; Olson, Kevin; Goldstein, Allen H.; Seco, Roger; Kim, Saewung; McAvey, Kevin; Shepson, Paul B.; Starn, Tim; Baumann, Karsten; Edgerton, Eric S.; Liu, Jiumeng; Shilling, John E.; Miller, David O.; Brune, William; Schobesberger, Siegfried; D'Ambro, Emma L.; Thornton, Joel A.

2016-01-01

Speciated particle-phase organic nitrates (pONs) were quantified using online chemical ionization MS during June and July of 2013 in rural Alabama as part of the Southern Oxidant and Aerosol Study. A large fraction of pONs is highly functionalized, possessing between six and eight oxygen atoms within each carbon number group, and is not the common first generation alkyl nitrates previously reported. Using calibrations for isoprene hydroxynitrates and the measured molecular compositions, we estimate that pONs account for 3% and 8% of total submicrometer organic aerosol mass, on average, during the day and night, respectively. Each of the isoprene- and monoterpenes-derived groups exhibited a strong diel trend consistent with the emission patterns of likely biogenic hydrocarbon precursors. An observationally constrained diel box model can replicate the observed pON assuming that pONs (i) are produced in the gas phase and rapidly establish gas–particle equilibrium and (ii) have a short particle-phase lifetime (∼2–4 h). Such dynamic behavior has significant implications for the production and phase partitioning of pONs, organic aerosol mass, and reactive nitrogen speciation in a forested environment. PMID:26811465

Recent progress in the genetics and epigenetics of paraoxonase: why it is relevant to children's environmental health.

PubMed

Holland, Nina; Lizarraga, Daneida; Huen, Karen

2015-04-01

Children are more susceptible to exposures in utero and during early childhood that may result in developmental problems and chronic diseases. Novel discoveries in the field of molecular epidemiology that can help explain susceptibility to exposures and disease will be demonstrated using the multifunctional enzyme paraoxonase 1 (PON1) as an example. The broad PON1 variability in humans, partly due to differences in genetics and age, can confer differential susceptibility because this enzyme can detoxify organophosphate pesticides and has antioxidant properties. Epigenetics plays a significant role in the mediation of the effects of environmental exposure on human health and is hypothesized to be a major contributing factor to the early-life origins of adult disease. Studies highlighted in this review demonstrate the relationship of PON1 polymorphisms with microRNA binding in addition to a link between DNA methylation in the transcriptional regulatory region with changes in PON1 enzyme levels. Other important methodologies such as ancestry informative markers and lactonase activity can enhance studies involving PON1. This PON1 model demonstrates that integrating genetic and epigenetic factors, as well as other novel methodologies, can improve our understanding of important susceptibility factors linked to pediatric disease.

[The role of lipoprotein-associated enzyme paraoxonase 1 and its polymorphisms in the pathogenesis of endothelial dysfunction and somatic complications in patients with alcoholism: Review ].

PubMed

Panchenko, L F; Baronets, V Yu; Naumova, T A; Pyrozhkov, S V; Terebilina, N N; Shoibonov, B B

2016-01-01

A review of recent data on the role of the multifunctional enzyme, associated with high density lipoproteins - paraoxonase 1 (PON1) in maintaining healthy endothelial function by detoxifying both oxidized low density lipoproteins and homocysteine thiolactone. The additional contribution to the protection of the endothelium against damage makes organophosphatase activity of PON1 involved in the detoxification products of tobacco smoke. The reduction of antioxidant activity of PON1 promotes the differentiation of monocytes into macrophages and the development of inflammation. The reduction of thiolactonase activity of PON1 is accompanied by a decrease of methionine re-synthesis from homocysteine causing DNA- hypomethylation and alteratioin of the expression patterns of pro- and anti-atherogenic genes. Global hypomethylation of the genome is regarded as one of the three most important mechanisms of the increased risk of somatic complications of alcoholism. The accumulation of homocysteine thiolactone serving agonist of glutamate receptors and antagonist of dopamine receptors is a prerequisite to increased alcohol abuse. Clinical observations focusing on gene polymorphisms of PON indicate that three different genotypes of polymorphism PON1Q192R have unequal degrees atheroprotective properties.

Paraoxonase 1 and oxidative stress in paediatric non-alcoholic steatohepatitis.

PubMed

Desai, Sonal; Baker, Susan S; Liu, Wensheng; Moya, Diana A; Browne, Richard W; Mastrandrea, Lucy; Baker, Robert D; Zhu, Lixin

2014-01-01

Non-alcoholic steatohepatitis (NASH) in children is a significant public health concern. Oxidative stress is an important component in the pathophysiology of NASH. Several enzymatic antioxidant mechanisms protect the liver from oxidative injury. Examination of the expression of these enzymes in NASH livers may provide insight on the roles for these antioxidant mechanisms in the pathophysiology of NASH. The mRNA expression of catalase, glutathione peroxidase 1 (GPX1), glutathione reductase (GSR), paraoxonase 1 (PON1) and other reactive oxygen species-related genes was evaluated by microarray and quantitative real-time PCR analyses. The PON1 protein levels were evaluated in liver and serum by Western blot analyses. Serum enzymatic activities of GPX, GSR and PON1 (paraoxonase and arylesterase activities) were examined. NASH livers exhibited elevated mRNA expression of catalase and PON1, but not GPX1 or GSR. No difference in serum GPX or GSR activity was detected between NASH patients and controls. Elevated expression of PON1 mRNA and protein was detected in NASH livers, but serum PON1 protein and activities were not elevated. Elevated expression of catalase and PON1 suggests protective roles for these antioxidants in NASH livers. Given the importance of oxidative stress in the pathophysiology of NASH, future studies focusing on these enzymes could identify important targets for therapeutic or preventive interventions for NASH patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ring-like reliable PON planning with physical constraints for a smart grid

NASA Astrophysics Data System (ADS)

Wang, Xin; Gu, Rentao; Ji, Yuefeng

2016-01-01

Due to the high reliability requirements in the communication networks of a smart grid, a ring-like reliable PON is an ideal choice to carry power distribution information. Economical network planning is also very important for the smart grid communication infrastructure. Although the ring-like reliable PON has been widely used in the real applications, as far as we know, little research has been done on the network optimization subject of the ring-like reliable PON. Most PON planning research studies only consider a star-like topology or cascaded PON network, which barely guarantees the reliability requirements of the smart grid. In this paper, we mainly investigate the economical network planning problem for the ring-like reliable PON of the smart grid. To address this issue, we built a mathematical model for the planning problem of the ring-like reliable PON, and the objective was to minimize the total deployment costs under physical constraints. The model is simplified such that all of the nodes have the same properties, except OLT, because each potential splitter site can be located in the same ONU position in power communication networks. The simplified model is used to construct an optimal main tree topology in the complete graph and a backup-protected tree topology in the residual graph. An efficient heuristic algorithm, called the Constraints and Minimal Weight Oriented Fast Searching Algorithm (CMW-FSA), is proposed. In CMW-FSA, a feasible solution can be obtained directly with oriented constraints and a few recursive search processes. From the simulation results, the proposed planning model and CMW-FSA are verified to be accurate (the error rates are less than 0.4%) and effective compared with the accurate solution (CAESA), especially in small and sparse scenarios. The CMW-FSA significantly reduces the computation time compared with the CAESA. The time complexity algorithm of the CMW-FSA is acceptable and calculated as T(n) = O(n3). After evaluating the effects of the parameters of the two PON systems, the total planning costs of each scenario show a general declining trend and reach a threshold as the respective maximal transmission distances and maximal time delays increase.

ONU Power Saving Scheme for EPON System

NASA Astrophysics Data System (ADS)

Mukai, Hiroaki; Tano, Fumihiko; Tanaka, Masaki; Kozaki, Seiji; Yamanaka, Hideaki

PON (Passive Optical Network) achieves FTTH (Fiber To The Home) economically, by sharing an optical fiber among plural subscribers. Recently, global climate change has been recognized as a serious near term problem. Power saving techniques for electronic devices are important. In PON system, the ONU (Optical Network Unit) power saving scheme has been studied and defined in XG-PON. In this paper, we propose an ONU power saving scheme for EPON. Then, we present an analysis of the power reduction effect and the data transmission delay caused by the ONU power saving scheme. According to the analysis, we propose an efficient provisioning method for the ONU power saving scheme which is applicable to both of XG-PON and EPON.

Efficient eNB inter-communication scheme in converged mobile and NG-PON2 system

NASA Astrophysics Data System (ADS)

Xiao, Simiao; Sun, Xiao; Zhang, Kaibin

2016-02-01

In LTE, a new X2-interface is defined to facilitate direct communication between neighboring eNBs. Since LTE is an all-IP network, the X2-interface traffic currently needs to be routed and transponded in L3 at the edge router by IP addressing. As mobile data increases, it is a promising trend to backhaul mobile services based on PON. In this paper, an effective approach for eNB inter-communication over TWDM-PON is proposed. By associating the IP address of eNB and the MAC address of ONU, the "inter-eNB communication in L3" can be mapped into "inter-ONU communication in L2" and transponded via the protocol of PON at the OLT. Thus, fast and cost-effective eNB inter-communication can be realized based on TWDM-PON within one wavelength channel and between different wavelength channels. The increasing data traffic pressure to the core network can also be alleviated.

Performance Enhancement of Bidirectional TWDM-PON by Rayleigh Backscattering Mitigation

NASA Astrophysics Data System (ADS)

Elewah, Ibrahim A.; Wadie, Martina N.; Aly, Moustafa H.

2018-01-01

A bidirectional time wavelength division multiplexing-passive optical network (TWDM-PON) with a centralized light source (CLS) is designed and evaluated. TWDM-PON is the promising solution for PON future expansion and migration. The most important issue that limits optical fiber transmission length is the interferometric noise caused by Rayleigh backscattering (RB). In this study, we demonstrate a TWDM-PON architecture with subcarrier at the remote node (RN) to mitigate the RB effect. A successful transmission with 8 optical channels is achieved using wavelength division multiplexing (WDM). Each optical channel is splitted into 8 time slots to achieve TWDM. The proposed scheme is operated over 20 km bidirectional single mode fiber (SMF). The proposed system has the advantage of expanding the downstream (DS) capacity to be 160 Gb/s (8 channels×20 Gb/s) and 20 Gb/s (8 channels×2.5 Gb/s) for the upstream (US) transmission capacity. This is accomplished by a remarkable bit error rate (BER) and low complexity.

Bidirectional multi-optical line terminals incorporated converged WSN-PON network using M/M/1 queuing

NASA Astrophysics Data System (ADS)

Kumar, Love; Sharma, Vishal; Singh, Amarpal

2017-12-01

Wireless Sensor Networks (WSNs) have an assortment of application areas, for instance, civil, military, and video surveillance with restricted power resources and transmission link. To accommodate the massive traffic load in hefty sensor networks is another key issue. Subsequently, there is a necessity to backhaul the sensed information of such networks and prolong the transmission link to access the distinct receivers. Passive Optical Network (PON), a next-generation access technology, comes out as a suitable candidate for the convergence of the sensed data to the core system. The earlier demonstrated work with single-OLT-PON introduces an overloaded buffer akin to video surveillance scenarios. In this paper, to combine the bandwidth potential of PONs with the mobility capability of WSNs, the viability for the convergence of PONs and WSNs incorporating multi-optical line terminals is demonstrated to handle the overloaded OLTs. The existing M/M/1 queue theory with interleaving polling with adaptive cycle time as dynamic bandwidth algorithm is used to shun the probability of packets clash. Further, the proposed multi-sink WSN and multi-OLT PON converged structure is investigated in bidirectional mode analytically and through computer simulations. The observations establish the proposed structure competent to accommodate the colossal data traffic through less time consumption.

Indices of paraoxonase and oxidative status do not enhance the prediction of subclinical cardiovascular disease in mixed-ancestry South Africans.

PubMed

Macharia, M; Kengne, A P; Blackhurst, D M; Erasmus, R T; Hoffmann, M; Matsha, T E

2014-01-01

We evaluated the association of indices of paraoxonase (PON1) and oxidative status with subclinical cardiovascular disease (CVD) in mixed-ancestry South Africans. Participants were 491 adults (126 men) who were stratified by diabetes status and body mass index (BMI). Carotid intima-media thickness (CIMT) was used as a measure of subclinical CVD. Indices of PON1 and oxidative status were determined by measuring levels and activities (paraoxonase and arylesterase) of PON1, antioxidant activity (ferric reducing antioxidant power and trolox equivalent antioxidant capacity), and lipid peroxidation markers (malondialdehyde and oxidized LDL). Diabetic subjects (28.9%) displayed a significant decrease in PON1 status and antioxidant activity as well as increase in oxidized LDL and malondialdehyde. A similar profile was apparent across increasing BMI categories. CIMT was higher in diabetic than nondiabetic subjects (P < 0.0001) but showed no variation across BMI categories. Overall, CIMT correlated negatively with indices of antioxidant activity and positively with measures of lipid oxidation. Sex, age, BMI, and diabetes altogether explained 29.2% of CIMT, with no further improvement from adding PON1 and/or antioxidant status indices. Though indices of PON1 and oxidative status correlate with CIMT, their measurements may not be useful for identifying subjects at high CVD risk in this population.

PON-Sol: prediction of effects of amino acid substitutions on protein solubility.

PubMed

Yang, Yang; Niroula, Abhishek; Shen, Bairong; Vihinen, Mauno

2016-07-01

Solubility is one of the fundamental protein properties. It is of great interest because of its relevance to protein expression. Reduced solubility and protein aggregation are also associated with many diseases. We collected from literature the largest experimentally verified solubility affecting amino acid substitution (AAS) dataset and used it to train a predictor called PON-Sol. The predictor can distinguish both solubility decreasing and increasing variants from those not affecting solubility. PON-Sol has normalized correct prediction ratio of 0.491 on cross-validation and 0.432 for independent test set. The performance of the method was compared both to solubility and aggregation predictors and found to be superior. PON-Sol can be used for the prediction of effects of disease-related substitutions, effects on heterologous recombinant protein expression and enhanced crystallizability. One application is to investigate effects of all possible AASs in a protein to aid protein engineering. PON-Sol is freely available at http://structure.bmc.lu.se/PON-Sol The training and test data are available at http://structure.bmc.lu.se/VariBench/ponsol.php mauno.vihinen@med.lu.se Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A flexible solution for the next generation EPON with hybrid bidirectional 1Gbps and 10Gbps

NASA Astrophysics Data System (ADS)

Zhang, Weixun; Qiao, Yaojun; Li, Hui; Ji, Yuefeng

2007-11-01

Ethernet PON (EPON) has been proved to be a successful technology among all the standardized PON systems [1, 2], in terms of its cost-effective and large bandwidth virtue. And EPON has become a network of a choice for subscriber oriented digital service delivery, taking over the market previously dominated by DSL. However, with the development of advanced video services, the bandwidth capacity of current EPON seems to be not well suited for the future large deployment of triple-play services. Many researches are now taken about the Next Generation EPON; and the recent 10G EPON system standardization effort in the IEEE [3] results a lot of interest in the evolution of current PON systems towards high data rate system capable of providing a future-proof platform for delivery of personalized triple-play services. In this paper, a novel architecture of TDM-based 10GE-PON system is proposed. It combines the GE-PON and 10GE-PON systems, and provides symmetric 1Gbps/10Gbps or asymmetric access simultaneously. According to the results of the simulation on the system throughput and latency performance, the system is verified to be one solution and an important step from 1Gbit/s to 10Gbit/s for the Next Generation EPON.

Adaptive upstream rate adjustment by RSOA-ONU depending on different injection power of seeding light in standard-reach and long-reach PON systems

NASA Astrophysics Data System (ADS)

Yeh, C. H.; Chow, C. W.; Shih, F. Y.; Pan, C. L.

2012-08-01

The wavelength division multiplexing-time division multiplexing (WDM-TDM) passive optical network (PON) using reflective semiconductor optical amplifier (RSOA)-based colorless optical networking units (ONUs) is considered as a promising candidate for the realization of fiber-to-the-home (FTTH). And this architecture is actively considered by Industrial Technology Research Institute (ITRI) for the realization of FTTH in Taiwan. However, different fiber distances and optical components would introduce different power budgets to different ONUs in the PON. Besides, due to the aging of optical transmitter (Tx), the power decay of the distributed optical carrier from the central office (CO) could also reduce the injection power into each ONU. The situation will be more severe in the long-reach (LR) PON, which is considered as an option for the future access. In this work, we investigate a WDM-TDM PON using RSOA-based ONU for upstream data rate adjustment depending on different continuous wave (CW) injection powers. Both standard-reach (25 km) and LR (100 km) transmissions are evaluated. Moreover, a detail analysis of the upstream signal bit-error rate (BER) performances at different injection powers, upstream data rates, PON split-ratios under stand-reach and long-reach is presented.

Hydrolysis of platelet-activating factor by human serum paraoxonase.

PubMed Central

Rodrigo, L; Mackness, B; Durrington, P N; Hernandez, A; Mackness, M I

2001-01-01

Human serum paraoxonase (human PON1) has been shown to be important in the metabolism of phospholipid and cholesteryl ester hydroperoxides, thereby preventing the oxidation of low-density lipoprotein (LDL) and retarding atherogenesis. However, the exact substrate specificity of PON1 has not been established. In the present study we show that purified PON1 hydrolyses platelet-activating factor (PAF). We could find no evidence for contamination of our preparation with authentic platelet-activating-factor acetylhydrolase (PAFAH) by immunoblotting with a PAFAH monoclonal antibody or by sequencing the purified protein. In addition the specific PAFAH inhibitor SB-222657 did not affect the ability of PON1 to hydrolyse PAF (30.1+/-2.8 micromol/min per mg of protein with no inhibitor; 31.4+/-2.2 micromol/min per mg of protein with 100 nM inhibitor) or phenyl acetate (242.6+/-30.8 versus 240.8+/-31.5 micromol/min per mg of protein with and without inhibitor respectively). SB-222657 was also unable to inhibit PAF hydrolysis by isolated human high-density lipoprotein (HDL), but completely abolished the activity of human LDL. Ostrich (Struthio camelus) HDL, which does not contain PON1, was unable to hydrolyse PAF. These data provide evidence that PON1 may limit the action of this bioactive pro-inflammatory phospholipid. PMID:11171072

Recent progress in the genetics and epigenetics of paraoxonase: why it is relevant to children’s environmental health

PubMed Central

Holland, N; Lizarraga, D; Huen, K

2015-01-01

Purpose of review Children are more susceptible to exposures in utero and during early childhood that may result in developmental problems and chronic diseases. Novel discoveries in the field of molecular epidemiology which can help explain susceptibility to exposures and disease will be demonstrated using the multifunctional enzyme paraoxonase (PON1) as an example. Recent findings The broad PON1 variability in humans, partly due to differences in genetics and age, can confer differential susceptibility because this enzyme can detoxify organophosphate pesticides and has antioxidant properties. Epigenetics plays a significant role in the mediation of the effects of environmental exposure on human health and is hypothesized to be a major contributing factor to the early-life origins of adult disease. Studies highlighted in this review demonstrate the relationship of PON1 polymorphisms with microRNA binding in addition to a link between DNA methylation in the transcriptional regulatory region with changes in PON1 enzyme levels. Other important methodologies such as ancestry informative markers and lactonase activity can enhance studies involving PON1. Summary This PON1 model demonstrates that integrating genetic and epigenetic factors as well as other novel methodologies can improve our understanding of important susceptibility factors linked to pediatric disease. PMID:25635583

PON1Q192R genetic polymorphism modifies organophosphorous pesticide effects on semen quality and DNA integrity in agricultural workers from southern Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez-Herrera, N.; Polanco-Minaya, H.; Salazar-Arredondo, E.

Pesticide exposure, including organophosphorous (OP) insecticides, has been associated with poor semen quality, and paraoxonase (PON1), an enzyme involved in OP deactivation, may have a role on their susceptibility, due to PON1 polymorphisms. Our objective was to evaluate the role of PON1Q192R polymorphism on the susceptibility to OP toxicity on semen quality and DNA integrity in agricultural workers. A cross-sectional study was conducted in farmers with Mayan ascendancy from southeastern Mexico chronically exposed to pesticides; mostly OP. Fifty four agricultural workers (18-55 years old) were included, who provided semen and blood samples. Semen quality was evaluated according to WHO, spermmore » DNA damage by in situ-nick translation (NT-positive cells), PON1Q192R polymorphism by real-time PCR and serum PON1 activity by using phenylacetate and paraoxon. Two OP exposure indexes were created: at the month of sampling and during 3 months before sampling, representing the exposure to spermatids-spermatozoa and to cells at one spermatogenic cycle, respectively. PON1 192R and 192Q allele frequencies were 0.54 and 0.46, respectively. Significant associations were found between OP exposure at the month of sampling and NT-positive cells and sperm viability in homozygote 192RR subjects, and dose-effect relationships were observed between OP exposure during 3 months before sampling and sperm quality parameters and NT-positive cells in homozygote 192RR farmers. This suggests that cells at all stages of spermatogenesis are target of OP, and that there exists an interaction between OP exposure and PON1Q192R polymorphism on these effects; farmers featuring the 192RR genotype were more susceptible to develop reproductive toxic effects by OP exposure.« less

Paraoxonase 2 Serves a Proapopotic Function in Mouse and Human Cells in Response to the Pseudomonas aeruginosa Quorum-sensing Molecule N-(3-Oxododecanoyl)-homoserine Lactone*

PubMed Central

Schwarzer, Christian; Fu, Zhu; Morita, Takeshi; Whitt, Aaron G.; Neely, Aaron M.; Li, Chi; Machen, Terry E.

2015-01-01

Pseudomonas aeruginosa use quorum-sensing molecules, including N-(3-oxododecanoyl)-homoserine lactone (C12), for intercellular communication. C12 activated apoptosis in mouse embryo fibroblasts (MEF) from both wild type (WT) and Bax/Bak double knock-out mice (WT MEF and DKO MEF that were responsive to C12, DKOR MEF): nuclei fragmented; mitochondrial membrane potential (Δψmito) depolarized; Ca2+ was released from the endoplasmic reticulum (ER), increasing cytosolic [Ca2+] (Cacyto); and caspase 3/7 was activated. DKOR MEF had been isolated from a nonclonal pool of DKO MEF that were non-responsive to C12 (DKONR MEF). RNAseq analysis, quantitative PCR, and Western blots showed that WT and DKOR MEF both expressed genes associated with cancer, including paraoxonase 2 (PON2), whereas DKONR MEF expressed little PON2. Adenovirus-mediated expression of human PON2 in DKONR MEF rendered them responsive to C12: Δψmito depolarized, Cacyto increased, and caspase 3/7 activated. Human embryonic kidney 293T (HEK293T) cells expressed low levels of endogenous PON2, and these cells were also less responsive to C12. Overexpression of PON2, but not PON2-H114Q (no lactonase activity) in HEK293T cells caused them to become sensitive to C12. Because [C12] may reach high levels in biofilms in lungs of cystic fibrosis (CF) patients, PON2 lactonase activity may control Δψmito, Ca2+ release from the ER, and apoptosis in CF airway epithelia. Coupled with previous data, these results also indicate that PON2 uses its lactonase activity to prevent Bax- and Bak-dependent apoptosis in response to common proapoptotic drugs like doxorubicin and staurosporine, but activates Bax- and Bak-independent apoptosis in response to C12. PMID:25627690

Study of bidirectional broadband passive optical network (BPON) using EDFA

NASA Astrophysics Data System (ADS)

Almalaq, Yasser

Optical line terminals (OLTs) and number of optical network units (ONUs) are two main parts of passive optical network (PON). OLT is placed at the central office of the service providers, the ONUs are located near to the end subscribers. When compared with point-to-point design, a PON decreases the number of fiber used and central office components required. Broadband PON (BPON), which is one type of PON, can support high-speed voice, data and video services to subscribers' residential homes and small businesses. In this research, by using erbium doped fiber amplifier (EDFA), the performance of bi-directional BPON is experimented and tested for both downstream and upstream traffic directions. Ethernet PON (E-PON) and gigabit PON (G-PON) are the two other kinds of passive optical network besides BPON. The most beneficial factor of using BPON is it's reduced cost. The cost of the maintenance between the central office and the users' side is suitable because of the use of passive components, such as a splitter in the BPON architecture. In this work, a bidirectional BPON has been analyzed for both downstream and upstream cases by using bit error rate analyzer (BER). BER analyzers test three factors that are the maximum Q factor, minimum bit error rate, and eye height. In other words, parameters such as maximum Q factor, minimum bit error rate, and eye height can be analyzed utilized a BER tester. Passive optical components such as a splitter, optical circulator, and filters have been used in modeling and simulations. A 12th edition Optiwave simulator has been used in order to analyze the bidirectional BPON system. The system has been tested under several conditions such as changing the fiber length, extinction ratio, dispersion, and coding technique. When a long optical fiber above 40km was used, an EDFA was used in order to improve the quality of the signal.

Paraoxonase 1 (PON1), agricultural organophosphate exposure, and Parkinson disease

PubMed Central

Manthripragada, Angelika D.; Costello, Sadie; Cockburn, Myles G.; Bronstein, Jeff M.; Ritz, Beate

2011-01-01

Background Human, animal and cell models support a role for pesticides in the etiology of Parkinson disease. Susceptibility to pesticides may be modified by genetic variants of xenobiotic enzymes, such as paraoxonase, that play a role in metabolizing some organophosphates. Methods We examined associations between Parkinson disease and the organophosphates diazinon, chlorpyrifos, and parathion, and the influence of a functional polymorphism at position 55 in the coding region of the PON1 gene (PON1-55). From 1 January 2001 through 1 January 2008, we recruited 351 incident cases and 363 controls from three rural California counties in a population-based case-control study. Participants provided a DNA sample, and residential exposure to organophosphates was determined from pesticide usage reports and a geographic information system (GIS) approach. We assessed the main effects of both genes and pesticides in unconditional logistic regression analyses, and evaluated the effect of carrying a PON1-55 MM variant on estimates of effects for diazinon, chlorpyrifos, and parathion exposures. Results Carriers of the variant MM PON1-55 genotype exposed to organophosphates exhibited a greater than 2-fold increase in Parkinson disease risk compared with persons who had the wildtype or heterozygous genotype and no exposure (for diazinon, odds ratio = 2.2 [95% confidence interval = 1.1–4.5]; for chlorpyrifos, 2.6 [1.3–5.4]). The effect estimate for chlorpyrifos, was more pronounced in younger-onset cases and controls (≤60 years) (5.3 [1.7–16]). No increase in risk was noted for parathion. Conclusion The increase in risk we observed among PON1-55 variant carriers for specific organophosphates metabolized by PON1 underscores the importance of considering susceptibility factors when studying environmental exposures in Parkinson disease. PMID:19907334

Decreased serum paraoxonase 1 (PON1) activity: an additional risk factor for atherosclerotic heart disease in patients with PCOS?

PubMed

Dursun, Polat; Demirtaş, Ezgi; Bayrak, Ahmet; Yarali, Hakan

2006-01-01

Patients with polycystic ovary syndrome (PCOS) may have an increased risk for the development of hypertension and atherosclerotic heart disease (AHD), the pathophysiological mechanisms of which are not clear. Paraoxonase1 (PON1) is a high-density lipoprotein-associated enzyme that prevents oxidative modification of low-density lipoprotein. The aim of this study was to measure the serum levels of PON1 activity in patients with PCOS and to compare with those of regularly cycling controls. Serum lipid parameters, malondialdehyde (MDA) levels and PON1 activity, were measured in PCOS patients (n = 23) and regularly cycling, age-, body mass index- and smoking status-matched controls (n = 23). All patients had normal glucose tolerance test as assessed by a 75 g oral glucose tolerance test. None of the patients had clinically evident hypertension or AHD. Apart from the mean serum PON1 activity, all parameters in the lipid profile including serum MDA levels were comparable between the two groups. There were no significant differences in respect to fasting glucose (4.64 +/- 0.5 versus 4.43 +/- 0.83 mmol/l) and fasting glucose insulin ratio (11.06 +/- 8.26 versus 11.49 +/- 4.90) among the two groups (P > 0.05). However, HOMA insulin resistance index was significantly higher in patients with PCOS compared with the controls (2.06 +/- 0.86 versus 1.51 +/- 0.49; P = 0.01). Also, mean serum PON1 activity was significantly lower in the PCOS group compared with the controls (151.2 +/- 90.8 versus 217.7 +/- 101.6, respectively; P = 0.027). Reduced serum PON1 activity might contribute to the increased susceptibility for the development of AHD in women with PCOS.

Paraoxonase lactonase activity (PON-HTLase), asymmetric dimethylarginine (ADMA) and platelet activating factor-acetylhydrolase (PAF-AH) activity in non-obese women with PCOS.

PubMed

Bayrak, Tulin; Dursun, Polat; Bayrak, Ahmet; Gültekin, Murat; Kolusarı, Ali; Cakır, Erdinç; Ozyurt, Merve; Zeyneloğlu, Hulusi B

2012-11-01

Paraoxonase1 (PON1), exhibits both esterase activity (PON1-AREase) and homocysteine thiolactonase activity (PON1-HTLase) which respectively prevent LDL oxidation and detoxify homocysteine thiolactone (HTL). Platelet-activating factor-acetylhydrolase (PAF-AH) is an antioxidant enzyme preventing LDL oxidation by hydrolysis of oxidized phospholipids. Both of these enzymes exhibit a proatherogenic role. ADMA is an endogenous inhibitor of nitric oxide (NO) synthesis causing endothelial dysfunction. The aim was to compare non-obese PCOS patients with a BMI matched control group using the following characteristics: serum PON1-HTLase, ADMA, PAF-AH, and lipid and hormonal parameters. 77 women with PCOS and 25 healthy subject were recruited for this study, The controls were non-obese BMI and age matched with the patients. There were no significant differences with respect to age, BMI, FSH, free testosterone, DHEA, androstenadion, total cholesterol, triglycerides, HDL, LDL, VLDL, fasting glucose/insulin ratio and HOMA-IR among the groups (p > 0.05). However, total testosterone and fasting glucose levels were significantly higher in the PCOS group (p < 0.05). On the other hand, PON1-HTLase levels (39.6 ± 5.77 vs. 33.8 ± 8.2, p = 0.02) were significantly lower in the PCOS group while ADMA levels (1.14 ± 0.6 vs. 3.37 ± 6.4, p = 0.004) were significantly higher in the PCOS group. However, there was no significant difference in PAF-AH activity among the groups. Decreased PON1-HTLase and increased ADMA levels might be a relevant marker for the development of future atherosclerotic heart disease (AHD) in non-obese PCOS patients. Further studies are needed to confirm our results.

Effect of paraoxonase 1 gene polymorphisms on clinical course of Henoch-Schönlein purpura.

PubMed

Yilmaz, Alev; Emre, Sevinc; Agachan, Bedia; Bilge, Ilmay; Yilmaz, Hulya; Ergen, Arzu; Isbir, Turgay; Sirin, Aydan

2009-01-01

Henoch-Schönlein purpura (HSP) is a systemic vasculitis; its pathogenesis is still unknown. Oxidative stress may play a role in the pathogenesis of HSP. Paraoxonase1 (PON1) is an antioxidant enzyme. Two polymorphisms have been defined in the coding region of the PON1 gene, Q/R192 and L/M55. In the present study, we aimed to investigate the effect of PON1 gene polymorphisms on the course and renal involvement of HSP in Turkish children. Forty-six patients with HSP were compared with 34 healthy children regarding the distribution of PON1 polymorphisms. PON1 Q/R192 genotype distribution was 58.6% QQ, 32.6% QR and 8.8% RR in the HSP group and 14.3% QQ, 50% QR and 35.7% RR in the control group. The frequency of QQ genotype was higher in the HSP group, and the presence of QQ genotype increased the risk by 3.42-fold for developing HSP (p=0.000, Fisher exact test; odds ratio [OR] = 2.048; 95% confidence interval [95% CI], 1.396-3.00). PON1 L/M55 genotype distribution was 50% LL, 43.5% LM and 6.5% MM in the HSP group and 48% LL, 26% LM and 26% MM in the control group. The frequency of MM genotype was lower in the HSP group, and the presence of MM genotype decreased the risk by 7.38-fold for developing HSP (p=0.009, Fisher exact test; OR=7.380, 95% CI, 1.474-36.953). PON1 polymorphisms may contribute to the pathogenesis and course of HSP, but we suggest that further investigations with larger patient groups are required to confirm our results.

A case control study on HDL associated PON1 enzyme level in Northern Indian type 2 diabetes mellitus patients.

PubMed

Wamique, Mohd; Ali, Wahid; Reddy, D Himanshu; Vishwakarma, Preeti; Waseem, Mohd

2018-03-22

To evaluate the serum paraoxonase 1 activity and determine its association with duration in type 2 Diabetes mellitus patients. A total of 80 cases from type 2 diabetes mellitus and healthy controls were enrolled in the present case control study. Human serum PON1 concentration was measured by ELISA and western blotting and it activity was determined spectrophotometrically using 4-nitrophenyle acetate. Diagnostic accuracy of serum PON1 to identify type 2 Diabetes mellitus was calculated with ROC analysis. Serum concentration of LDL, VLDL, TG, A1C, FBS and TC levels showed significantly higher levels in type 2 diabetes patients as compared to healthy controls, however there were no significant differences found in the level of HDL. Serum PON1 concentration and activity monitored in patients with >1 year diabetes showed higher level (75.1 ± 6.8 ng/mL) as compared to patients with >3 years diabetes (65.24 ± 1.6 ng/mL), its level was further decreased in patients with >5 (53.8 ± 2.6 ng/mL) and >7 years (48.1 ± 2.7 ng/mL) of diabetes. PON1 concentration decreased as the duration of diabetes increased. PON1 level was further decreased due to habits like smoking and alcohol consumption. Serum PON1 levels decrease in states of high oxidative stress like metabolic syndrome, obesity, uncontrolled diabetes, and dyslipidemia. It can be used as diagnostic marker for diabetes mellitus along with increased TG, LDL, VLDL and FBG. Copyright © 2018. Published by Elsevier Ltd.

Effects of a Preconditioning Oral Nutritional Supplement on Pig Livers after Warm Ischemia

PubMed Central

Nickkholgh, Arash; Li, Zhanqing; Yi, Xue; Mohr, Elvira; Liang, Rui; Mikalauskas, Saulius; Gross, Marie-Luise; Zorn, Markus; Benzing, Steffen; Schneider, Heinz; Büchler, Markus W.; Schemmer, Peter

2012-01-01

Background. Several approaches have been proposed to pharmacologically ameliorate hepatic ischemia/reperfusion injury (IRI). This study was designed to evaluate the effects of a preconditioning oral nutritional supplement (pONS) containing glutamine, antioxidants, and green tea extract on hepatic warm IRI in pigs. Methods. pONS (70 g per serving, Fresenius Kabi, Germany) was dissolved in 250 mL tap water and given to pigs 24, 12, and 2 hrs before warm ischemia of the liver. A fourth dose was given 3 hrs after reperfusion. Controls were given the same amount of cellulose with the same volume of water. Two hours after the third dose of pONS, both the portal vein and the hepatic artery were clamped for 40 min. 0.5, 3, 6, and 8 hrs after reperfusion, heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), portal venous flow (PVF), hepatic arterial flow (HAF), bile flow, and transaminases were measured. Liver tissue was taken 8 hrs after reperfusion for histology and immunohistochemistry. Results. HR, MAP, CVP, HAF, and PVF were comparable between the two groups. pONS significantly increased bile flow 8 hrs after reperfusion. ALT and AST were significantly lower after pONS. Histology showed significantly more severe necrosis and neutrophil infiltration in controls. pONS significantly decreased the index of immunohistochemical expression for TNF-α, MPO, and cleaved caspase-3 (P < 0.001). Conclusion. Administration of pONS before and after tissue damage protects the liver from warm IRI via mechanisms including decreasing oxidative stress, lipid peroxidation, apoptosis, and necrosis. PMID:22791934

Elevated Pontine and Putamenal GABA Levels in Mild-Moderate Parkinson Disease Detected by 7 Tesla Proton MRS

PubMed Central

Emir, Uzay E.; Tuite, Paul J.; Öz, Gülin

2012-01-01

Background Parkinson disease (PD) is characterized by the degeneration of nigrostriatal dopaminergic neurons. However, postmortem evidence indicates that the pathology of lower brainstem regions, such as the pons and medulla, precedes nigral involvement. Consistently, pontomedullary damage was implicated by structural and PET imaging in early PD. Neurochemical correlates of this early pathological involvement in PD are unknown. Methodology/Principal Finding To map biochemical alterations in the brains of individuals with mild-moderate PD we quantified neurochemical profiles of the pons, putamen and substantia nigra by 7 tesla (T) proton magnetic resonance spectroscopy. Thirteen individuals with idiopathic PD (Hoehn & Yahr stage 2) and 12 age- and gender-matched healthy volunteers participated in the study. γ-Aminobutyric acid (GABA) concentrations in the pons and putamen were significantly higher in patients (N = 11, off medications) than controls (N = 11, p<0.001 for pons and p<0.05 for putamen). The GABA elevation was more pronounced in the pons (64%) than in the putamen (32%). No other neurochemical differences were observed between patients and controls. Conclusion/Significance The GABA elevation in the putamen is consistent with prior postmortem findings in patients with PD, as well as with in vivo observations in a rodent model of PD, while the GABA finding in the pons is novel. The more significant GABA elevation in the pons relative to the putamen is consistent with earlier pathological involvement of the lower brainstem. This study provides in vivo evidence for an alteration in the GABAergic tone in the lower brainstem and striatum in early-moderate PD, which may underlie disease pathogenesis and may provide a biomarker for disease staging. PMID:22295119

The Search for Dietary Supplements to Elevate or Activate Circulating Paraoxonases

PubMed Central

Lou-Bonafonte, José M.; Gabás-Rivera, Clara; Navarro, María A.; Osada, Jesús

2017-01-01

Low levels of paraoxonase 1 (PON1) have been associated with the development of several pathological conditions, whereas high levels have been shown to be anti-atherosclerotic in mouse models. These findings suggest that PON1 could be a good surrogate biomarker. The other members of the family, namely PON2 and PON3, the role of which has been much less studied, deserve more attention. This paper provides a systematic review of current evidence concerning dietary supplements in that regard. Preliminary studies indicate that the response to dietary supplements may have a nutrigenetic aspect that will need to be considered in large population studies or in clinical trials. A wide range of plant preparations have been found to have a positive action, with pomegranate and some of its components being the best characterized and Aronia melanocarpa one of the most active. Flavonoids are found in the composition of all active extracts, with catechins and genistein being the most promising agents for increasing PON1 activity. However, some caveats regarding the dose, length of treatment, bioavailability, and stability of these compounds in formulations still need to be addressed. Once these issues have been resolved, these compounds could be included as nutraceuticals and functional foods capable of increasing PON1 activity, thereby helping with the long-term prevention of atherosclerosis and other chronic ailments. PMID:28212288

Serum butyrylcholinesterase and paraoxonase 1 in a canine model of endotoxemia: effects of choline administration.

PubMed

Tvarijonaviciute, Asta; Kocaturk, Meric; Cansev, Mehmet; Tecles, Fernando; Ceron, Jose J; Yilmaz, Zeki

2012-10-01

Butyrylcholinesterase (BChE) and paraoxonase 1 (PON1) are two serum enzymes synthesized by the liver that are related with inflammation. The main objectives of this study were to determine changes in serum BChE and PON1 by using a canine model of endotoxemia, and to evaluate whether choline alters BChE and PON1 activities during inflammation. For this purpose, a total of 20 mongrel dogs were divided into four groups: control, choline (C), lipopolysaccharide (LPS), and LPS+C. Dogs in the control group were injected with 0.9% NaCl (0.2 ml/kg, i.v.). Dogs in C and LPS+C groups received choline chloride (20 mg/kg, i.v., three times with 4 h intervals). Endotoxin was injected (0.02 mg/kg, i.v., once) to the dogs of LPS and LPS+C groups. Statistically significant decreases in BChE and PON1 activities in LPS group were detected 24 and 48 h post injection, respectively. No statistically significant changes in BChE and PON1 activities at different times were detected in control, C, or LPS+C groups. In conclusion, the data obtained in present study revealed a decrease in serum BChE and PON1 activities in dogs during experimentally induced endotoxemia and that choline administration attenuates these changes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Biomarkers of Sensitivity and Exposure in Washington State Pesticide Handlers

PubMed Central

Keifer, M.C.; Checkoway, H.; De Roos, A.J.; Farin, F.M.; Fenske, R.A.; Richter, R.J.; van Belle, G.; Furlong, C.E.

2011-01-01

Organophosphate (OP) and N-methyl-carbamate (CB) insecticides are widely used in agriculture in the US and abroad. These compounds – which inhibit acetylcholinesterase (AChE) enzyme activity – continue to be responsible for a high proportion of pesticide poisonings among US agricultural workers. It is possible that some individuals may be especially susceptible to health effects related to OP/CB exposure. The paraoxonase (PON1) enzyme metabolizes the highly toxic oxon forms of some OPs, and an individual's PON1 status may be an important determinant of his or her sensitivity to these chemicals. This chapter discusses methods used to characterize individual PON1 status and reviews previous epidemiologic studies that have evaluated PON1-related sensitivity to OPs in relation to various health endpoints. It also describes an ongoing longitudinal study among OP-exposed agricultural pesticide handlers who are participating in a recently implemented cholinesterase monitoring program in Washington State. This study will evaluate handlers' PON1 status as a hypothesized determinant of butyrylcholinesterase (BuChE) inhibition. Such studies will be useful to determine how regulatory risk assessments might account for differences in PON1-related OP sensitivity when characterizing inter-individual variability in risk related to OP exposure. Recent work assessing newer and more sensitive biomarkers of OP exposure is also discussed briefly in this chapter. PMID:20221867

The Search for Dietary Supplements to Elevate or Activate Circulating Paraoxonases.

PubMed

Lou-Bonafonte, José M; Gabás-Rivera, Clara; Navarro, María A; Osada, Jesús

2017-02-15

Low levels of paraoxonase 1 (PON1) have been associated with the development of several pathological conditions, whereas high levels have been shown to be anti-atherosclerotic in mouse models. These findings suggest that PON1 could be a good surrogate biomarker. The other members of the family, namely PON2 and PON3, the role of which has been much less studied, deserve more attention. This paper provides a systematic review of current evidence concerning dietary supplements in that regard. Preliminary studies indicate that the response to dietary supplements may have a nutrigenetic aspect that will need to be considered in large population studies or in clinical trials. A wide range of plant preparations have been found to have a positive action, with pomegranate and some of its components being the best characterized and Aronia melanocarpa one of the most active. Flavonoids are found in the composition of all active extracts, with catechins and genistein being the most promising agents for increasing PON1 activity. However, some caveats regarding the dose, length of treatment, bioavailability, and stability of these compounds in formulations still need to be addressed. Once these issues have been resolved, these compounds could be included as nutraceuticals and functional foods capable of increasing PON1 activity, thereby helping with the long-term prevention of atherosclerosis and other chronic ailments.

Proposal of DCS-OFDM-PON upstream transmission with intensity modulator and collective self-coherent detection

NASA Astrophysics Data System (ADS)

Zhang, Jing; Yang, Heming; Zhao, Difu; Qiu, Kun

2016-07-01

We introduce digital coherent superposition (DCS) into optical access network and propose a DCS-OFDM-PON upstream transmission scheme using intensity modulator and collective self-coherent detection. The generated OFDM signal is real based on Hermitian symmetry, which can be used to estimate the common phase error (CPE) by complex conjugate subcarrier pairs without any pilots. In simulation, we transmit an aggregated 40 Gb/s optical OFDM signal from two ONUs. The transmission performance with DCS is slightly better after 25 km transmission without relative transmission time delay. The fiber distance for different ONUs to RN are not same in general and there is relative transmission time delay between ONUs, which causes inter-carrier-interference (ICI) power increasing and degrades the transmission performance. The DCS can mitigate the ICI power and the DCS-OFDM-PON upstream transmission outperforms the conventional OFDM-PON. The CPE estimation is by using two pairs of complex conjugate subcarriers without redundancy. The power variation can be 9 dB in DCS-OFDM-PON, which is enough to tolerate several kilometers fiber length difference between the ONUs.

Effect of nandrolone decanonate on paraoxonase activity in hemodialysis patients.

PubMed

Ghorbanihaghjo, Amir; Argani, Hassan; Rahbaninoubar, Mohammad; Rashtchizadeh, Nadereh

2005-12-01

This study was designed to determine the effect of nandrolone decanonate (ND) on HDL-C, apolipoproteins and paraoxonase (PON) activity in stable hemodialysis patients. 64 hemodialysis patients were treated with ND at a dose of 100 mg/I.M./week for 4 months. HDL-C, Apo-AI, Apo B, concentrations and PON activity were measured before and after 2 and 4 months of treatment as well as 2 months after withdrawing the treatment. After 4 months of treatment, an elevation in the serum levels of Apo B (P<0.0001) and a marked decrease in the concentration of HDL-C (P<0.0001), Apo-AI (P<0.0001) and PON activity (P<0.0001) were found. A significant correlation between PON and both Apo-AI (r=0.270, P<0.04) and HDL-C (r=0.455, P<0.0001) and also between HDL-C and Apo-AI (r=0.305, P<0.02) were found. Results revealed the adverse effects of ND on apolipoprotein levels in our study population. It is possible that ND reduces PON activity mostly by reducing both the HDL-C and Apo-AI levels.

The radio-on-fiber-wavelength-division-multiplexed-passive-optical network (WDM-RoF-PON) for wireless and wire layout with linearly-polarized dual-wavelength fiber laser and carrier reusing

NASA Astrophysics Data System (ADS)

Ji, Wei; Chang, Jun

2013-07-01

In this paper, we design a WDM-RoF-PON based on linearly-polarized dual-wavelength fiber laser and CSRZ-DPSK, which can achieve wire-line and wireless access synchronously. With the CSRZ-DPSK modulation, the wireless access in ONU can save RF source and the frequency of radio carrier can be controlled by OLT. The dual-wavelength fiber laser is the union light source of WDM-PON with polarization multiplexing. By the RSOA and downstream light source reusing, the ONU can save omit laser source and makes the WDM-PON to be colorless. The networking has the credible transmission property, including wireless access and fiber transmission. The networking also has excellent covering range.

Molecular Evolution of Human PON to Design Enhanced Catalytic Efficiency for Hydrolysis of Nerve Agents

DTIC Science & Technology

2011-12-01

8   C.   Catalytic activity of evolved variants with GA ................................................................. 11   D...several variants of rePON1 with enhanced activity towards a racemic mixture of CMP-Coumarin by screening ‘neutral drift’ libraries of rePON1 (e.g. 1G3, 2G9...22. The most active variant was 3B3, which had ~250-fold higher catalytic efficiency (kcat/Km 20x106 M-1min-1) compared to the wild-type-like

Structure/Function Analyses of Human Serum Paraoxonase (HuPON1) Mutants Designed from a DFPase-Like Homology Model

DTIC Science & Technology

2004-08-23

purified HuPON1 Substitution of amino acid residues in the HuPONI enzyme was accomplished by PCR-based site-directed Two methods were utilized to...including organophosphates and lactones, and exhibits anti-atherogenic properties. A few amino acids have been shown to be essential for the enzyme’s...not been assigned to those residues. Based on scquence-structure alignment studies, we have folded the amino acid sequence of HuPON I onto the sixfold

The contribution of nitrogen fixation by cyanobacteria to particulate organic nitrogen in a constructed wetland

NASA Astrophysics Data System (ADS)

Zhang, X.; PAN, X.; MA, M.; Li, W.; Cui, L.

2016-12-01

N-fixing cyanobacteria can create extra nitrogen for aquatic ecosystems. Previous studies reported inconsistence patterns of the contribution of biological nitrogen fixation to the nitrogen pools in aquatic ecosystems. However, there were few studies concerning the effect of fixed nitrogen by cyanobacteria on the nitrogen removal efficiency in constructed wetlands. This study was performed at the Beijing Wildlife Rescue and Rehabilitation Centre, where a constructed lake for the habitation of waterfowls and a constructed wetland for purifying sewage from the lake are located. The composition of phytoplankton communities, the concentrations of particulate organic nitrogen (PON) and nitrogen fixation rates (Rn) in the constructed lake and the constructed wetland were compared throughout a growing season. We counted the densities of genus Anabaena and Microcystis cells, and explored their relationships with PON and Rn in water. The proportions of PON from various sources, including the ambient N2, waterfowl faeces, wetland sediments and the nitrates, were calculated by the natural abundance of 15N with the IsoSource software. The result revealed that the constructed lake was alternately dominated by Anabaena and Microcystis throughout the growing season, and the Rn was positively correlated with PON and the cell density of Anabaena (P < 0.05). This implied that the fixed nitrogen by N-fixing Anabaena might be utilized by non-N-fixing Microcystis, maintaining the fixed nitrogen with PON form. The ambient N2 composed 0.5 82% and 50.0 84.7% to the PON in the constructed lake and wetland respectively during the growing season. The proportions of PON from N2 increased to more than 80% when the Rn reached the highest in September. The result demonstrated that the nitrogen fixed by Anabaena might be utilized by non-N-fixing Microcystis which formed water blooms in summer. Therefore, the decline of the removal efficiency of PON in the constructed wetland in summer might indirectly result from the nitrogen fixation, since the proliferated algal were difficult to sediment in surface flow wetlands.

Use of Pom Pons to Illustrate Cubic Crystal Structures.

ERIC Educational Resources Information Center

Cady, Susan G.

1997-01-01

Describes a method that uses olefin pom pons to illustrate cubic crystal structure. Facilitates hands-on examination of different packing arrangements such as hexagonal close-packed and cubic close-packed structures. (JRH)

The effects and mechanism of flavonoid-rePON1 interactions. Structure-activity relationship study.

PubMed

Atrahimovich, Dana; Vaya, Jacob; Khatib, Soliman

2013-06-01

Flavonoids are plant phenolic secondary metabolites that are widely distributed in the human diet. These antioxidants have received much attention because of their neuroprotective, cardioprotective, and chemopreventive actions. While a major focus has been on the flavonoids' antioxidant properties, there is an emerging view that many of the potential health benefits of flavonoids and their in vivo metabolites are due to modulatory actions in cells through direct interactions with proteins, and not necessarily due to their antioxidant function. This view relies on the observations that flavonoids are present in the circulation at very low concentrations, which are not sufficient to exert effective antioxidant effects. The enzyme paraoxonase 1 (PON1) is associated with high-density lipoprotein (HDL), and is responsible for many of HDLs' antiatherogenic properties. We previously showed that the flavonoid glabridin binds to rePON1 and affects the enzyme's 3D structure. This interaction protects the enzyme from inhibition by an atherogenic component of the human carotid plaque. Here, we broadened our study to an investigation of the structure-activity relationships (SARs) of 12 flavonoids from different subclasses with rePON1 using Trp-fluorescence quenching, modeling calculations and Cu(2+)-induced low-density lipoprotein (LDL) oxidation methods. Our findings emphasize the 'protein-binding' mechanism by which flavonoids exert their beneficial biological role toward rePON1. Flavonoids' capacity to interact with the enzyme's rePON1 hydrophobic groove mostly dictates their pro/antioxidant behavior. Copyright © 2013 Elsevier Ltd. All rights reserved.

Demonstration of flexible multicasting and aggregation functionality for TWDM-PON

NASA Astrophysics Data System (ADS)

Chen, Yuanxiang; Li, Juhao; Zhu, Paikun; Zhu, Jinglong; Tian, Yu; Wu, Zhongying; Peng, Huangfa; Xu, Yongchi; Chen, Jingbiao; He, Yongqi; Chen, Zhangyuan

2017-06-01

The time- and wavelength-division multiplexed passive optical network (TWDM-PON) has been recognized as an attractive solution to provide broadband access for the next-generation networks. In this paper, we propose flexible service multicasting and aggregation functionality for TWDM-PON utilizing multiple-pump four-wave-mixing (FWM) and cyclic arrayed waveguide grating (AWG). With the proposed scheme, multiple TWDM-PON links share a single optical line terminal (OLT), which can greatly reduce the network deployment expense and achieve efficient network resource utilization by load balancing among different optical distribution networks (ODNs). The proposed scheme is compatible with existing TDM-PON infrastructure with fixed-wavelength OLT transmitter, thus smooth service upgrade can be achieved. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment with 10-Gb/s OOK and 10-Gb/s QPSK orthogonal frequency division multiplexing (OFDM) signal multicasting and aggregating to seven PON links. Compared with back-to-back (BTB) channel, the newly generated multicasting OOK signal and OFDM signal have power penalty of 1.6 dB and 2 dB at the BER of 10-3, respectively. For the aggregation of multiple channels, no obvious power penalty is observed. What is more, to verify the flexibility of the proposed scheme, we reconfigure the wavelength selective switch (WSS) and adjust the number of pumps to realize flexible multicasting functionality. One to three, one to seven, one to thirteen and one to twenty-one multicasting are achieved without modifying OLT structure.

Dietary Polyphenols Increase Paraoxonase 1 Gene Expression by an Aryl Hydrocarbon Receptor-Dependent Mechanism

PubMed Central

Gouédard, Cédric; Barouki, Robert; Morel, Yannick

2004-01-01

Human paraoxonase 1 (PON-1) is a serum high-density lipoprotein-associated enzyme mainly secreted by the liver. It has endogenous and exogenous substrates and displays protective properties with respect to cardiovascular disease and organophosphate intoxication. In the HuH7 human hepatoma cell line, PON-1 activity and mRNA levels were increased by dietary polyphenolic compounds such as quercetin but also by toxic ligands of the aryl hydrocarbon receptor (AhR) such as 3-methylcholanthrene (3-MC). However, the 2,3,7,8-tetrachlorobenzo(p)dioxin (TCDD) was a poor inducer. Transient and stable transfection assays indicated that these compounds increased the PON-1 gene promoter activity in an AhR-dependent manner, since their effect was inhibited by 7-keto-cholesterol and AhR-directed short interfering RNA. Deletions and mutations studies showed that a xenobiotic responsive element (XRE)-like sequence within the PON-1 promoter mediated the effect of 3-MC and quercetin. In contrast with consensus XREs from the cytochrome P450 1A1 gene, the PON-1 XRE-like element mediated preferentially the effect of quercetin compared to the results seen with TCDD. Furthermore, AhR binding to this element was preferentially activated by quercetin. These observations provide a molecular mechanism for the regulation of the cardioprotective enzyme PON-1 by polyphenols. They suggest also that AhR ligands may differentially regulate gene expression depending on the DNA target sequence. PMID:15169886

Role of Paraoxonase 1 Activity and Oxidative/Antioxidative Stress Markers in Patients with Acute Cerebral Infarction.

PubMed

Zhu, Hui; Zhao, Teng; Liu, Jingyao

2018-06-01

Paraoxonase1 (PON1) is an antioxidant which confers antioxidant properties to high-density lipoprotein (HDL) and prevents low-density lipoprotein (LDL) oxidation. The purpose of this study was to evaluate the activities of PON1 and oxidative/antioxidative stress markers in acute cerebral infarction. In this study, 161 patients diagnosed with acute cerebral infarction and 161 gender- and age-matched healthy controls were recruited. Based on the clinicoradiological profiles, the patients were further classified into two groups: lacunar infarction group and large-artery atherosclerosis group. We measured the individual lipid status parameters, oxidative and antioxidative stress status parameters, and PON1 activity. Serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and oxidative stress parameters in patients with acute cerebral infarction were significantly higher than those in the normal controls (p < 0.05). High-density lipoprotein cholesterol (HDL-C) level, PON1 activity, superoxide dismutase (SOD) activity, and antioxidative stress parameters in patients were lower than in the normal controls (p < 0.05). Superoxide anion (O2-), malondialdehyde (MDA), and PON1 levels in the lacunar infarction group were lower than in the large-artery atherosclerosis group (p < 0.05). Oxidative stress markers and PON1 activity are sensitive indicators of acute cerebral infarction. Our findings suggest a severely impaired antioxidative protection mechanism in these patients. Our study provides new insights into the pathophysiological mechanisms of acute cerebral infarction, which may also provide new therapeutic targets for ischemic cerebrovascular diseases.

Neuro-protective effect of rutin against Cisplatin-induced neurotoxic rat model.

PubMed

Almutairi, Mashal M; Alanazi, Wael A; Alshammari, Musaad A; Alotaibi, Moureq Rashed; Alhoshani, Ali R; Al-Rejaie, Salim Salah; Hafez, Mohamed M; Al-Shabanah, Othman A

2017-09-29

Cisplatin is widely used chemotherapeutic agent for cancer treatment with limited uses due to its neurotoxic side effect. The aim of this study was to determine the potential preventive effects of rutin on the brain of cisplatin- neurotoxic rat model. Forty rats were divided into four groups. Group-1 (control group) was intra-peritoneal (IP) injected with 2.5 ml/kg saline. Group-2 (rutin group) was orally administrated 30 mg/kg rutin dissolved in water for 14 days. Group-3 (cisplatin group) was IP received 5 mg/kg cisplatin single dose. Group-4 (rutin and cisplatin group) was orally administrated 30 mg/kg rutin dissolved in water for 14 days with a single dose of 5 mg/kg cisplatin IP on day ten. Brain tissues from frontal cortex was used to extract RNA, the gene expression levels of paraoxonase-1 (PON-1), PON-2, PON-3, peroxisome proliferator-activated receptor delta (PPAR-δ), and glutathione peroxidase (GPx) was investigated by Real-time PCR. Cisplatin significantly decreased the expression levels of PON-1, PON-3, PPAR-δ and GPX whereas significantly increased PON-2 expression levels. Co-administration of Rutin prevented the cisplatin-induced toxicity by restoring the alteration in the studied genes to normal values as in the control group. This study showed that Rutin has neuroprotective effect and reduces cisplatin- neurotoxicity with possible mechanism via the antioxidant pathway.

PON1 and Mediterranean Diet

PubMed Central

Lou-Bonafonte, José M.; Gabás-Rivera, Clara; Navarro, María A.; Osada, Jesús

2015-01-01

The Mediterranean diet has been proven to be highly effective in the prevention of cardiovascular diseases. Paraoxonase 1 (PON1) has been implicated in the development of those conditions, especially atherosclerosis. The present work describes a systematic review of current evidence supporting the influence of Mediterranean diet and its constituents on this enzyme. Despite the differential response of some genetic polymorphisms, the Mediterranean diet has been shown to exert a protective action on this enzyme. Extra virgin olive oil, the main source of fat, has been particularly effective in increasing PON1 activity, an action that could be due to low saturated fatty acid intake, oleic acid enrichment of phospholipids present in high-density lipoproteins that favor the activity, and increasing hepatic PON1 mRNA and protein expressions induced by minor components present in this oil. Other Mediterranean diet constituents, such as nuts, fruits and vegetables, have been effective in modulating the activity of the enzyme, pomegranate and its compounds being the best characterized items. Ongoing research on compounds isolated from all these natural products, mainly phenolic compounds and carotenoids, indicates that some of them are particularly effective, and this may enhance the use of nutraceuticals and functional foods capable of potentiating PON1 activity. PMID:26024295

The transmission of symmetric 40 Gb/s TWDM-based NG-PON2 utilizing delay interferometer (DI) for RSOA bandwidth enhancement

NASA Astrophysics Data System (ADS)

Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, AbuSahmah M.

2016-07-01

Time and wavelength-division multiplexed passive optical network (TWDM-PON) has been finally selected as the pragmatic solution for the next-generation passive optical network stage 2 (NG-PON2). In this paper, we propose a symmetric 40 Gb/s TWDM-PON system with low cost reflective semiconductor optical amplifier (RSOA) for both downstream and upstream directions. A single bi-pass delay interferometer (DI), deployed in the optical line terminal (OLT), is used to enhance the poor performance of the RSOA with respect to the low bandwidth induced by laser chirp. With the help of the 40 GHz free spectrum range (FSR) DI, we show a successful transmission of the proposed work through simulation study where an aggregate capacity of 40 Gb/s is transported over 40 km transmission distance with 32 splits. The TWDM-PON system at BER of 10-6 has shown a minimum receiver sensitivity of -22.78 dBm and -22.71 dBm for both downstream and upstream, respectively with maximum power penalty of 2 dB for downstream channel and 2.39 dB for upstream channel.

Pons to Posterior Cingulate Functional Projections Predict Affective Processing Changes in the Elderly Following Eight Weeks of Meditation Training.

PubMed

Shao, Robin; Keuper, Kati; Geng, Xiujuan; Lee, Tatia M C

2016-08-01

Evidence indicates meditation facilitates affective regulation and reduces negative affect. It also influences resting-state functional connectivity between affective networks and the posterior cingulate (PCC)/precuneus, regions critically implicated in self-referential processing. However, no longitudinal study employing active control group has examined the effect of meditation training on affective processing, PCC/precuneus connectivity, and their association. Here, we report that eight-week meditation, but not relaxation, training 'neutralized' affective processing of positive and negative stimuli in healthy elderly participants. Additionally, meditation versus relaxation training increased the positive connectivity between the PCC/precuneus and the pons, the direction of which was largely directed from the pons to the PCC/precuneus, as revealed by dynamic causal modeling. Further, changes in connectivity between the PCC/precuneus and pons predicted changes in affective processing after meditation training. These findings indicate meditation promotes self-referential affective regulation based on increased regulatory influence of the pons on PCC/precuneus, which new affective-processing strategy is employed across both resting state and when evaluating affective stimuli. Such insights have clinical implications on interventions on elderly individuals with affective disorders. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Decreased paraoxonase1 activity and increased malondialdehyde and oxidative DNA damage levels in primary open angle glaucoma

PubMed Central

Mumcu, Ugur Yilmaz; Kocer, Ibrahim; Ates, Orhan; Alp, H. Hakan

2016-01-01

To investigate the malondialdehyde (MDA) levels, paraoxonase1 (PON1) activity and 8-hydroxy 2-deoxyguanosine (8-OHdG) levels in the primary open angle glaucoma (POAG) patient. Blood samples from 52 healthy individuals and 53 patients with POAG were analyzed for MDA and 8-OHdG by HPLC (high-performance liquid chromatography) and PON1 by spectrophotometry. The data obtained were analyzed statistically. MDA levels were 10.46±8.4 and 4.70±1.79 µmol; PON1 levels were 121±39.55 and 161.62±60.22 U/mL; and 8-OHdG values were 1.32±0.53/106 dG and 0.47±0.27/106 dG in the POAG patients and the control group, respectively. The difference was significant in MDA levels, 8-OHdG levels and PON1 activity in POAG patients in comparison with controls (P<0.001). We concluded that the observed increase in MDA and 8-OHdG levels may be correlated with decreased PON1 activity. Oxidative stress plays an important role in glaucoma development. PMID:27803873

PON1 and Mediterranean Diet.

PubMed

Lou-Bonafonte, José M; Gabás-Rivera, Clara; Navarro, María A; Osada, Jesús

2015-05-27

The Mediterranean diet has been proven to be highly effective in the prevention of cardiovascular diseases. Paraoxonase 1 (PON1) has been implicated in the development of those conditions, especially atherosclerosis. The present work describes a systematic review of current evidence supporting the influence of Mediterranean diet and its constituents on this enzyme. Despite the differential response of some genetic polymorphisms, the Mediterranean diet has been shown to exert a protective action on this enzyme. Extra virgin olive oil, the main source of fat, has been particularly effective in increasing PON1 activity, an action that could be due to low saturated fatty acid intake, oleic acid enrichment of phospholipids present in high-density lipoproteins that favor the activity, and increasing hepatic PON1 mRNA and protein expressions induced by minor components present in this oil. Other Mediterranean diet constituents, such as nuts, fruits and vegetables, have been effective in modulating the activity of the enzyme, pomegranate and its compounds being the best characterized items. Ongoing research on compounds isolated from all these natural products, mainly phenolic compounds and carotenoids, indicates that some of them are particularly effective, and this may enhance the use of nutraceuticals and functional foods capable of potentiating PON1 activity.

Experimental investigation of colorless ONU employing superstructured fiber Bragg gratings in WDM/OCDMA-PON

NASA Astrophysics Data System (ADS)

Wang, Dawei; Cheng, Liang; Chen, Biao

2009-11-01

Colorless optical network unit (ONU) is a very important concept for the wavelength division multiplexing (WDM) based passive optical networks (PON). We present a novel scheme to construct non-wavelength-selective ONUs in WDM/OCDMA-PON by making use of the broad spectrum band of superstructure fiber Bragg gratings (SSFBGs). The experiment results reveal that the spectrum-sliced encoded signals from different wavelength channels can be successfully decoded with the same SSFBGs, and thus the proposed colorless ONU scheme is proved to be feasible.

Optical signal suppression by a cascaded SOA/RSOA for wavelength reusing reflective PON upstream transmission.

PubMed

Jung, Sang Min; Mun, Kyoung Hak; Kang, Soo Min; Han, Sang Kook

2017-09-18

An optical signal suppression technique based on a cascaded SOA and RSOA is proposed for the reflective passive optical networks (PONs) with wavelength division multiplexing (WDM). By suppressing the downstream signal of the optical carrier, the proposed reflective PON effectively reuses the downstream optical carrier for upstream signal transmission. As an experimental demonstration, we show that the proposed optical signal suppression technique is effective in terms of the signal bandwidth and bit-error-rate (BER) performance of the remodulated upstream transmission.

Oxidant-antioxidant status in Egyptian children with sickle cell anemia: a single center based study.

PubMed

El-Ghamrawy, Mona Kamal; Hanna, Wagdi Maurice; Abdel-Salam, Amina; El-Sonbaty, Marwa M; Youness, Eman R; Adel, Ahmed

2014-01-01

the present study was conducted to investigate the oxidant-antioxidant status in Egyptian children with sickle cell anemia. the serum levels of total antioxidant capacity (TAO), paraoxonase (PON), vitamin E, nitrite, and malondialdehyde (MDA) were measured in 40 steady state children with homozygous sickle cell anemia (24 males and 16 females) and 20 apparently healthy age- and gender-matched controls. mean serum TAO, PON, vitamin E, and nitrite levels were significantly lower in the group with sickle cell anemia, whereas mean serum MDA was significantly higher in these children compared to controls. No significant differences in mean levels of TAO, PON, nitrite, vitamin E, and MDA were found in sickle cell anemia patients receiving hydroxyurea when compared with those not receiving hydroxyurea. A significant negative correlation between serum nitrite and the occurrence of vaso-occlusive crises (VOC) was observed (r=-0.3, p=0.04). PON level was found to be positively correlated with patients' weight and BMI (r=-0.4, p=0.01; r=-0.7, p<0.001, respectively), but not with frequency of VOC. The area under the curve of serum nitrite in predicting occurrence of VOC was 0.782, versus 0.701 for PON, and 0.650 for TAO (p=0.006). Serum MDA was not correlated with nitrite, PON, TAO, or vitamin E levels. No significant correlations were detected between serum nitrite and hemoglobin or antioxidant enzymes. children with sickle cell anemia have chronic oxidative stress that may result in increased VOC, and decreased serum nitrite may be associated with increases in VOC frequency. A novel finding in this study is the decrease in PON level in these patients, which is an interesting subject for further research. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Performance analysis of TCP traffic and its influence on ONU's energy saving in energy efficient TDM-PON

NASA Astrophysics Data System (ADS)

Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; Lee, Joohyung; Uddin, Mohammad Rakib; Lee, Gyu Myoung; Choi, Jun Kyun

2015-12-01

The majority of the traffic over the Internet is TCP based, which is very sensitive to packet loss and delay. Existing research efforts in TDM-Passive Optical Networks (TDM-PONs) mostly evaluate energy saving and traffic delay performances under different energy saving solutions. However, to the best of our knowledge, how energy saving mechanisms could affect TCP traffic performance in TDM-PONs has hardly been studied. In this paper, by means of our state-of-art OPNET Modular based TDM-PON simulator, we evaluate TCP traffic delay, throughput, and Optical Network Unit (ONU) energy consumption performances in a TDM-PON where energy saving mechanisms are employed in ONUs. Here, we study the performances under commonly used energy saving mechanisms defined in standards for TDM-PONs: cyclic sleep and doze mode. In cyclic sleep mode, we evaluate the performances under two well-known sleep interval length deciding algorithms (i.e. fixed sleep interval (FSI) and exponential sleep interval deciding (ESID)) that an OLT uses to decide sleep interval lengths for an ONU. Findings in this paper put forward the strong relationship among TCP traffic delay, throughput and ONU energy consumption under different sleep interval lengths. Moreover, we reveal that under high TCP traffic, both FSI and ESID will end up showing similar delay, energy and throughput performance. Our findings also show that doze mode can offer better TCP throughput and delay performance at the price of consuming more energy than cyclic sleep mode. In addition, our results provide a glimpse on understanding at what point doze mode becomes futile in improving energy saving of an ONU under TCP traffic. Furthermore, in this paper, we highlight important research issues that should be studied in future research to maximize energy saving in TDM-PONs while meeting traffic Quality of Service requirements.

p.Q192R SNP of PON1 seems not to be Associated with Carotid Atherosclerosis Risk Factors in an Asymptomatic and Normolipidemic Brazilian Population Sample

PubMed Central

Scherrer, Daniel Zanetti; Zago, Vanessa Helena de Souza; Vieira, Isabela Calanca; Parra, Eliane Soler; Panzoldo, Natália Baratella; Alexandre, Fernanda; Secolin, Rodrigo; Baracat, Jamal; Quintão, Eder Carlos Rocha; de Faria, Eliana Cotta

2015-01-01

Background Evidences suggest that paraoxonase 1 (PON1) confers important antioxidant and anti-inflammatory properties when associated with high-density lipoprotein (HDL). Objective To investigate the relationships between p.Q192R SNP of PON1, biochemical parameters and carotid atherosclerosis in an asymptomatic, normolipidemic Brazilian population sample. Methods We studied 584 volunteers (females n = 326, males n = 258; 19-75 years of age). Total genomic DNA was extracted and SNP was detected in the TaqMan® SNP OpenArray® genotyping platform (Applied Biosystems, Foster City, CA). Plasma lipoproteins and apolipoproteins were determined and PON1 activity was measured using paraoxon as a substrate. High-resolution β-mode ultrasonography was used to measure cIMT and the presence of carotid atherosclerotic plaques in a subgroup of individuals (n = 317). Results The presence of p.192Q was associated with a significant increase in PON1 activity (RR = 12.30 (11.38); RQ = 46.96 (22.35); QQ = 85.35 (24.83) μmol/min; p < 0.0001), HDL-C (RR= 45 (37); RQ = 62 (39); QQ = 69 (29) mg/dL; p < 0.001) and apo A-I (RR = 140.76 ± 36.39; RQ = 147.62 ± 36.92; QQ = 147.49 ± 36.65 mg/dL; p = 0.019). Stepwise regression analysis revealed that heterozygous and p.192Q carriers influenced by 58% PON1 activity towards paraoxon. The univariate linear regression analysis demonstrated that p.Q192R SNP was not associated with mean cIMT; as a result, in the multiple regression analysis, no variables were selected with 5% significance. In logistic regression analysis, the studied parameters were not associated with the presence of carotid plaques. Conclusion In low-risk individuals, the presence of the p.192Q variant of PON1 is associated with a beneficial plasma lipid profile but not with carotid atherosclerosis. PMID:26039660

Crystal structures of the transpeptidase domain of the Mycobacterium tuberculosis penicillin-binding protein PonA1 reveal potential mechanisms of antibiotic resistance.

PubMed

Filippova, Ekaterina V; Kieser, Karen J; Luan, Chi-Hao; Wawrzak, Zdzislaw; Kiryukhina, Olga; Rubin, Eric J; Anderson, Wayne F

2016-06-01

Mycobacterium tuberculosis is a human respiratory pathogen that causes the deadly disease tuberculosis. The rapid global spread of antibiotic-resistant M. tuberculosis makes tuberculosis infections difficult to treat. To overcome this problem new effective antimicrobial strategies are urgently needed. One promising target for new therapeutic approaches is PonA1, a class A penicillin-binding protein, which is required for maintaining physiological cell wall synthesis and cell shape during growth in mycobacteria. Here, crystal structures of the transpeptidase domain, the enzymatic domain responsible for penicillin binding, of PonA1 from M. tuberculosis in the inhibitor-free form and in complex with penicillin V are reported. We used site-directed mutagenesis, antibiotic profiling experiments, and fluorescence thermal shift assays to measure PonA1's sensitivity to different classes of β-lactams. Structural comparison of the PonA1 apo-form and the antibiotic-bound form shows that binding of penicillin V induces conformational changes in the position of the loop β4'-α3 surrounding the penicillin-binding site. We have also found that binding of different antibiotics including penicillin V positively impacts protein stability, while other tested β-lactams such as clavulanate or meropenem resulted in destabilization of PonA1. Our antibiotic profiling experiments indicate that the transpeptidase activity of PonA1 in both M. tuberculosis and M. smegmatis mediates tolerance to specific cell wall-targeting antibiotics, particularly to penicillin V and meropenem. Because M. tuberculosis is an important human pathogen, these structural data provide a template to design novel transpeptidase inhibitors to treat tuberculosis infections. Structural data are available in the PDB database under the accession numbers 5CRF and 5CXW. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

p.Q192R SNP of PON1 seems not to be Associated with Carotid Atherosclerosis Risk Factors in an Asymptomatic and Normolipidemic Brazilian Population Sample.

PubMed

Scherrer, Daniel Zanetti; Zago, Vanessa Helena de Souza; Vieira, Isabela Calanca; Parra, Eliane Soler; Panzoldo, Natália Baratella; Alexandre, Fernanda; Secolin, Rodrigo; Baracat, Jamal; Quintão, Eder Carlos Rocha; Faria, Eliana Cotta de

2015-07-01

Evidences suggest that paraoxonase 1 (PON1) confers important antioxidant and anti-inflammatory properties when associated with high-density lipoprotein (HDL). To investigate the relationships between p.Q192R SNP of PON1, biochemical parameters and carotid atherosclerosis in an asymptomatic, normolipidemic Brazilian population sample. We studied 584 volunteers (females n = 326, males n = 258; 19-75 years of age). Total genomic DNA was extracted and SNP was detected in the TaqMan® SNP OpenArray® genotyping platform (Applied Biosystems, Foster City, CA). Plasma lipoproteins and apolipoproteins were determined and PON1 activity was measured using paraoxon as a substrate. High-resolution β-mode ultrasonography was used to measure cIMT and the presence of carotid atherosclerotic plaques in a subgroup of individuals (n = 317). The presence of p.192Q was associated with a significant increase in PON1 activity (RR = 12.30 (11.38); RQ = 46.96 (22.35); QQ = 85.35 (24.83) μmol/min; p < 0.0001), HDL-C (RR= 45 (37); RQ = 62 (39); QQ = 69 (29) mg/dL; p < 0.001) and apo A-I (RR = 140.76 ± 36.39; RQ = 147.62 ± 36.92; QQ = 147.49 ± 36.65 mg/dL; p = 0.019). Stepwise regression analysis revealed that heterozygous and p.192Q carriers influenced by 58% PON1 activity towards paraoxon. The univariate linear regression analysis demonstrated that p.Q192R SNP was not associated with mean cIMT; as a result, in the multiple regression analysis, no variables were selected with 5% significance. In logistic regression analysis, the studied parameters were not associated with the presence of carotid plaques. In low-risk individuals, the presence of the p.192Q variant of PON1 is associated with a beneficial plasma lipid profile but not with carotid atherosclerosis.

PON1 L55M and Q192R gene polymorphisms and CAD risks in patients with hyperlipidemia : Clinical study of possible associations.

PubMed

Chen, H; Ding, S; Zhou, M; Wu, X; Liu, X; Liu, J; Wu, Y; Liu, D

2017-08-23

A decreased plasma high density lipoprotein (HDL) cholesterol level is a strong risk factor for coronary artery disease (CAD). Antioxidant activity of HDL mainly lies in the activity of paraoxonase (PON). This study aimed to investigate the relationships between PON1 L55M and Q192R polymorphisms, and the risks of CAD in patients with hyperlipidemia. From January 2014 to January 2016, 244 patients were divided into hyperlipidemia, hyperlipidemia + CAD, and control groups. The hyperlipidemia and hyperlipidemia + CAD groups were designated as the case group. Serum PON1 concentrations were measured using the enzyme-linked immunosorbent assay. After isolating genomic DNA, the PON1 L55M and Q192R genes were amplified by polymerase chain reaction and sequenced. In the case group, the genotypes LM and LL were detected significantly more often than in the control group, as were the alleles R (33.33%, 42.12%) and L (22.78%, 29.11%). The frequency of QR and RR genotypes was significantly higher in the hyperlipidemia + CAD group than in the hyperlipidemia group; the allele R in the hyperlipidemia + CAD group (42.77%) was more frequent than in the hyperlipidemia group (23.78%). The Q192R polymorphism was associated with low serum PON1 concentrations, and the lowest concentration was observed in the 192QR + 192RR genotype (P = 0.03). Logistic regression analysis showed a significant correlation between the 192R allele and smoking (P = 0.03), body mass index (P = 0.02), systolic blood pressure (P = 0.004), total cholesterol (P = 0.03), triglycerides (P = 0.01), HDL (P = 0.004), and low density lipoprotein (P = 0.02). The PON1 alleles 192R and 55L are associated with CAD, and the Q192R polymorphism may be a risk factor for CAD.

Altered lipid peroxidation markers are related to post-traumatic stress disorder (PTSD) and not trauma itself in earthquake survivors.

PubMed

Atli, Abdullah; Bulut, Mahmut; Bez, Yasin; Kaplan, İbrahim; Özdemir, Pınar Güzel; Uysal, Cem; Selçuk, Hilal; Sir, Aytekin

2016-06-01

The traumatic life events, including earthquakes, war, and interpersonal conflicts, cause a cascade of psychological and biological changes known as post-traumatic stress disorder (PTSD). Malondialdehyde (MDA) is a reliable marker of lipid peroxidation, and paraoxonase is a known antioxidant enzyme. The aims of this study were to investigate the relationship between earthquake trauma, PTSD effects on oxidative stress and the levels of serum paraoxonase 1 (PON1) enzyme activity, and levels of serum MDA. The study was carried out on three groups called: the PTSD group, the traumatized with earthquake exercise group, and healthy control group, which contained 32, 31, and 38 individuals, respectively. Serum MDA levels and PON1 enzyme activities from all participants were measured, and the results were compared across all groups. There were no significant differences between the PTSD patients and non-PTSD earthquake survivors in terms of the study variables. The mean PON1 enzyme activity from PTSD patients was significantly lower, while the mean MDA level was significantly higher than that of the healthy control group (p < 0.01 for both measurements). Similarly, earthquake survivors who did not develop PTSD showed higher MDA levels and lower PON1 activity when compared to healthy controls. However, the differences between these groups did not reach a statistically significant level. Increased MDA level and decreased PON1 activity measured in PTSD patients after earthquake and may suggest increased oxidative stress in these patients. The nonsignificant trends that are observed in lipid peroxidation markers of earthquake survivors may indicate higher impact of PTSD development on these markers than trauma itself. For example, PTSD diagnosis seems to add to the effect of trauma on serum MDA levels and PON1 enzyme activity. Thus, serum MDA levels and PON1 enzyme activity may serve as biochemical markers of PTSD diagnosis.

Three-mode mode-division-multiplexing passive optical network over 12-km low mode-crosstalk FMF using all-fiber mode MUX/DEMUX

NASA Astrophysics Data System (ADS)

Ren, Fang; Li, Juhao; Wu, Zhongying; Hu, Tao; Yu, Jinyi; Mo, Qi; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

2017-01-01

We propose three-mode mode-division-multiplexing passive optical network (MDM-PON) based on low mode-crosstalk few-mode fiber (FMF) and all-fiber mode multiplexer/demultiplexer (MUX/DEMUX). The FMF with step-index profile is designed and fabricated for effectively three-independent-spatial-mode transmission and low mode-crosstalk for MDM-PON transmission. The all-fiber mode MUX/DEMUX are composed of cascaded mode selective couplers (MSCs), which simultaneously multiplex or demultiplex multiple modes. Based on the low mode-crosstalk of the FMF and all-fiber mode MUX/DEMUX, each optical network unit (ONU) communicates with the optical line terminal (OLT) independently utilizing a different optical linearly polarized (LP) spatial mode in MDM-PON system. We experimentally demonstrate MDM-PON transmission of three independent-spatial-modes over 12-km FMF with 10-Gb/s optical on-off keying (OOK) signal and direct detection.

TWC and AWG based optical switching structure for OVPN in WDM-PON

NASA Astrophysics Data System (ADS)

Bai, Hui-feng; Chen, Yu-xin; Wang, Qin

2015-03-01

With the rapid development of optical elements with large capacity and high speed, the network architecture is of great importance in determing the performance of wavelength division multiplexing passive optical network (WDM-PON). This paper proposes a switching structure based on the tunable wavelength converter (TWC) and the arrayed-waveguide grating (AWG) for WDM-PON, in order to provide the function of opitcal virtual private network (OVPN). Using the tunable wavelength converter technology, this switch structure is designed and works between the optical line terminal (OLT) and optical network units (ONUs) in the WDM-PON system. Moreover, the wavelength assignment of upstream/downstream can be realized and direct communication between ONUs is also allowed by privite wavelength channel. Simulation results show that the proposed TWC and AWG based switching structure is able to achieve OVPN function and to gain better performances in terms of bite error rate (BER) and time delay.

High performance sandwich structured Si thin film anodes with LiPON coating

NASA Astrophysics Data System (ADS)

Luo, Xinyi; Lang, Jialiang; Lv, Shasha; Li, Zhengcao

2018-06-01

The sandwich structured silicon thin film anodes with lithium phosphorus oxynitride (LiPON) coating are synthesized via the radio frequency magnetron sputtering method, whereas the thicknesses of both layers are in the nanometer range, i.e. between 50 and 200 nm. In this sandwich structure, the separator simultaneously functions as a flexible substrate, while the LiPON layer is regarded as a protective layer. This sandwich structure combines the advantages of flexible substrate, which can help silicon release the compressive stress, and the LiPON coating, which can provide a stable artificial solid-electrolyte interphase (SEI) film on the electrode. As a result, the silicon anodes are protected well, and the cells exhibit high reversible capacity, excellent cycling stability and good rate capability. All the results demonstrate that this sandwich structure can be a promising option for high performance Si thin film lithium ion batteries.

High performance sandwich structured Si thin film anodes with LiPON coating

NASA Astrophysics Data System (ADS)

Luo, Xinyi; Lang, Jialiang; Lv, Shasha; Li, Zhengcao

2018-04-01

The sandwich structured silicon thin film anodes with lithium phosphorus oxynitride (LiPON) coating are synthesized via the radio frequency magnetron sputtering method, whereas the thicknesses of both layers are in the nanometer range, i.e. between 50 and 200 nm. In this sandwich structure, the separator simultaneously functions as a flexible substrate, while the LiPON layer is regarded as a protective layer. This sandwich structure combines the advantages of flexible substrate, which can help silicon release the compressive stress, and the LiPON coating, which can provide a stable artificial solidelectrolyte interphase (SEI) film on the electrode. As a result, the silicon anodes are protected well, and the cells exhibit high reversible capacity, excellent cycling stability and good rate capability. All the results demonstrate that this sandwich structure can be a promising option for high performance Si thin film lithium ion batteries.

PON1 polymorphisms are associated with polycystic ovary syndrome susceptibility, related traits, and PON1 activity in Indian women with the syndrome.

PubMed

Dadachanji, Roshan; Shaikh, Nuzhat; Khavale, Sushma; Patil, Anushree; Shah, Nalini; Mukherjee, Srabani

2015-07-01

To investigate the association of paraoxonase 1 (PON1) polymorphisms (L55M and Q192R) with polycystic ovary syndrome (PCOS) susceptibility and its related traits in Indian women. Case-control study. Academic research institute, infertility, and endocrinology clinics. Controls (n = 326), women with PCOS (n = 482). None. Genotypic and allelic frequency distribution, genotype-phenotype association, different PON1 activities (lactonase, arylesterase, and paraoxonase). The genotypic and allelic frequency distributions of the L55M polymorphism were significantly different between lean controls and lean women with PCOS, and this polymorphism reduced the risk of PCOS development in lean but not in obese Indian women. Furthermore, this polymorphism was significantly associated with decreased 2-hour glucose, apolipoprotein B, free and bioavailable T, and free androgen index concurrent with increased sex hormone-binding globulin (SHBG) and FSH levels only in lean women with PCOS. However, Q192R polymorphism showed comparable genotypic frequency distribution between controls and women with PCOS. PON1 lactonase and arylesterase activities were significantly decreased in women with PCOS compared with controls. PON1 polymorphisms were shown to influence its activities. Our study showed that L55M, but not Q192R, polymorphism is significantly associated with reduced PCOS susceptibility only in lean women and also impacts glucose metabolism, lipid parameters, and hyperandrogenemia in them. Our study therefore suggests the possibility of differential genetic pathophysiology of PCOS between lean and obese women. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

All-optical virtual private network system in OFDM based long-reach PON using RSOA re-modulation technique

NASA Astrophysics Data System (ADS)

Kim, Chang-Hun; Jung, Sang-Min; Kang, Su-Min; Han, Sang-Kook

2015-01-01

We propose an all-optical virtual private network (VPN) system in an orthogonal frequency division multiplexing (OFDM) based long reach PON (LR-PON). In the optical access network field, technologies based on fundamental upstream (U/S) and downstream (D/S) have been actively researched to accommodate explosion of data capacity. However, data transmission among the end users which is arisen from cloud computing, file-sharing and interactive game takes a large weight inside of internet traffic. Moreover, this traffic is predicted to increase more if Internet of Things (IoT) services are activated. In a conventional PON, VPN data is transmitted through ONU-OLT-ONU via U/S and D/S carriers. It leads to waste of bandwidth and energy due to O-E-O conversion in the OLT and round-trip propagation between OLT and remote node (RN). Also, it causes inevitable load to the OLT for electrical buffer, scheduling and routing. The network inefficiency becomes more critical in a LR-PON which has been researched as an effort to reduce CAPEX and OPEX through metro-access consolidation. In the proposed system, the VPN data is separated from conventional U/S and re-modulated on the D/S carrier by using RSOA in the ONUs to avoid bandwidth consumption of U/S and D/S unlike in previously reported system. Moreover, the transmitted VPN data is re-directed to the ONUs by wavelength selective reflector device in the RN without passing through the OLT. Experimental demonstration for the VPN communication system in an OFDM based LR-PON has been verified.

Oral preoperative antioxidants in pancreatic surgery: a double-blind, randomized, clinical trial.

PubMed

Braga, Marco; Bissolati, Massimiliano; Rocchetti, Simona; Beneduce, Aldo; Pecorelli, Nicolò; Di Carlo, Valerio

2012-02-01

Oxidative stress due to ischemia/reperfusion injury increases systemic inflammation and impairs immune defenses. Much interest has developed for the administration of antioxidant substrates in surgical patients. The purpose of this study was to perform a pilot evaluation of the impact of a carbohydrate- containing preconditioning oral nutritional supplement (pONS) enriched with glutamine, antioxidants, and green tea extract on postoperative oxidative stress. We performed a double-blind placebo-controlled randomized clinical trial, involving 36 cancer patients undergoing pancreaticoduodenectomy. Patients were randomized to receive either pONS or placebo twice the day before surgery and once 3 hours before surgery. Total endogenous antioxidant capacity (TEAC), plasma levels of vitamin C, vitamin E, selenium, zinc, F2-isoprostanes, and C-reactive protein were measured at baseline and on postoperative day (POD) 1, 3, and 7. At surgery, the mean gastric residual volume (mL) was 54.2 in the pONS group versus 51.3 in the placebo group (P = NS). On POD 1 plasma levels of vitamin C (P = 0.001), selenium (P = 0.07), and zinc (P = 0.06) were higher in the pONS group compared to placebo. TEAC was improved on POD 1, 3, and 7 in the pONS group compared to placebo (P = 0.01). No difference was found in plasma C-reactive protein levels after surgery in both groups. Perioperative pONS administration positively affected plasma vitamin C levels and improved TEAC shortly after surgery, but did not reduce oxidative stress and systemic inflammation markers. Copyright © 2012 Elsevier Inc. All rights reserved.

Serum Paraoxonase-1 Concentration as a Potential Predictor of Urinary Bladder Cancer Recurrence. A Five Year Follow-Up Study.

PubMed

Iftimie, Simona; García-Heredia, Anabel; Pujol-Bosch, Francesc; Pont-Salvadó, Antoni; López-Azcona, Ana Felisa; Hernández-Aguilera, Anna; Cabré, Noemí; Luciano-Mateo, Fedra; Fort-Gallifa, Isabel; Castro, Antoni; Camps, Jordi; Joven, Jorge

2018-04-23

This study provides preliminary information on the usefulness of measuring serum paraoxonase-1 (PON1) concentration and activity (and other inflammatory markers) to predict tumor recurrence in patients with urinary bladder cancer. We studied a total of 39 hospitalized patients in whom the diagnosis of urinary bladder cancer was confirmed by transurethral resection. After five years of follow-up, 29 patients presented with tumor recurrence. As control subjects, we also studied 61 healthy subjects and a further 132 hospitalized patients who had a urinary catheter-related infection due to causes other than cancer. Results showed that urinary bladder patients had lower serum PON1 concentration and activity, and higher chemokine (C-C motif) ligand 2, C-reactive protein, and procalcitonin concentrations than the control individuals. Patients with tumor recurrence had significantly lower serum PON1 concentration than patients without tumor recurrence. The mean area under the curve of the receiver operating characteristics plot for serum PON1 concentration in discriminating patients with and those without tumor recurrence was 0.755 and the best combination of sensitivity and specificity was obtained at PON1 = 100 mg/L (0.72 and 0.80, respectively). Establishing this value as a cut-off, positive predictive value was = 0.91, and negative predictive value was = 0.50. These results suggest that the measurement of serum PON1 concentration may be a high-sensitivity marker of tumor recurrence in urinary bladder cancer patients. Copyright © 2018 IMSS. Published by Elsevier Inc. All rights reserved.

Two-dimensional priority-based dynamic resource allocation algorithm for QoS in WDM/TDM PON networks

NASA Astrophysics Data System (ADS)

Sun, Yixin; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Rao, Lan

2018-01-01

Wavelength division multiplexing/time division multiplexing (WDM/TDM) passive optical networks (PON) is being viewed as a promising solution for delivering multiple services and applications. The hybrid WDM / TDM PON uses the wavelength and bandwidth allocation strategy to control the distribution of the wavelength channels in the uplink direction, so that it can ensure the high bandwidth requirements of multiple Optical Network Units (ONUs) while improving the wavelength resource utilization. Through the investigation of the presented dynamic bandwidth allocation algorithms, these algorithms can't satisfy the requirements of different levels of service very well while adapting to the structural characteristics of mixed WDM / TDM PON system. This paper introduces a novel wavelength and bandwidth allocation algorithm to efficiently utilize the bandwidth and support QoS (Quality of Service) guarantees in WDM/TDM PON. Two priority based polling subcycles are introduced in order to increase system efficiency and improve system performance. The fixed priority polling subcycle and dynamic priority polling subcycle follow different principles to implement wavelength and bandwidth allocation according to the priority of different levels of service. A simulation was conducted to study the performance of the priority based polling in dynamic resource allocation algorithm in WDM/TDM PON. The results show that the performance of delay-sensitive services is greatly improved without degrading QoS guarantees for other services. Compared with the traditional dynamic bandwidth allocation algorithms, this algorithm can meet bandwidth needs of different priority traffic class, achieve low loss rate performance, and ensure real-time of high priority traffic class in terms of overall traffic on the network.

Methods for measuring serum activity levels of the 192 Q and R isoenzymes of paraoxonase 1 in QR heterozygous individuals.

PubMed

Teiber, John F; Kramer, Gerald L; Haley, Robert W

2013-08-01

Paraoxonase 1 (PON1), an esterase that hydrolyzes toxic organophosphates and has antioxidative and antiatherogenic properties, contains a common polymorphism at position 192: glutamine (Q) or arginine (R). The Q and R isoenzymes exhibit different physical and protective properties. We describe 2 methods for quantifying their serum activity levels. We measured serum hydrolytic activity with paraoxon [paraoxonase (PXN) activity], phenylacetate [arylesterase (AE) activity], and diazoxon [diazoxonase (DZN) activity] with standard automated assays. We determined PON1 Q192R genotypes with PCR and Q192R phenotypes using the PXN/AE and PXN/DZN ratios. Interpolation equations were empirically derived to predict the percentage of total PON1 hydrolytic activity due to the Q isoenzyme (%Q) from the PXN/AE and PXN/DZN ratios; %R is 100 - %Q. We estimated Q and R isoenzyme activity levels in sera from 2095 veterans by multiplying AE activity, a measure of total PON1 hydrolytic activity, by %Q and %R. In all 2095 samples, the PXN/AE and PXN/DZN ratios predicted Q192R phenotypes with nearly identical accuracy (κ = 0.997). In the 925 QR heterozygotes, the 2 interpolation methods predicted Q and R isoenzyme activity levels with excellent agreement (intraclass correlation 0.94). After excluding a few genotype/phenotype-discordant samples, the percentage of total PON1 activity due to the Q isoenzyme ranged from 22% to 70%. These new interpolation methods allow accurate estimation of PON1 192 Q and R isoenzyme activity levels, increasing specificity and power for studying susceptibility to disease.

The Influence of Monoterpene and Isoprene Nitrates on the Chemistry and Phase State of Secondary Organic Aerosol in a Low-NOx Mixed Deciduous/Coniferous Forest

NASA Astrophysics Data System (ADS)

Slade, J. H., Jr.; Shepson, P. B.; Desrochers, S. J.; Harvey, R. M.; Wallace, W.; Bui, A.; Griffin, R. J.; Kavassalis, S.; Shi, Q.; Murphy, J. G.; Cook, R.; Connor, M.; Ault, A. P.; Pratt, K.; Alwe, H. D.; Millet, D. B.; Bertman, S. B.; Stevens, P. S.; Wennberg, P. O.; Boor, B.; Petrucci, G.

2016-12-01

Particle phase state plays a key role in secondary organic aerosol (SOA) growth, reactive uptake of gas-phase radicals, and condensed phase reactions, influencing atmospheric composition and clouds. While biogenic SOA derived from isoprene and monoterpene oxidation can exhibit glassy or highly viscous semisolid phase states depending on relative humidity, the lifetimes of important SOA precursors including organic nitrates (ON) can depend on the liquid water content (LWC) and particle acidity. Reactions such as acid-catalyzed hydrolysis of particulate ON (pON) are especially sensitive to changes in aerosol LWC. However, the role of particle phase state on the chemistry of pON, and the chemical transformations of pON on the phase of SOA are poorly understood. During the summer of 2016, as part of the PROPHET - Atmospheric Measurements of Oxidants in Summer (AMOS) field study in a northern Michigan mixed deciduous/coniferous forest, we investigated the production of isoprene (IN) and monoterpene nitrates (MTN) at the ground and canopy levels and their role in particle formation, growth, and phase using a combination of high-resolution chemical ionization and aerosol mass spectrometry techniques, size distribution measurements, and particle bounce factors (BF) using two electrical low pressure impactors operating in parallel. Preliminary derived BF suggest the particles may be in a liquid-like state similar to those measured in other high-humidity and isoprene-rich regions such as the Amazon and Southeastern US. However, maxima in BF are observed during periods of high pON, NO, and IN during the day and high NO2 and MTN at night. Some periods were marked with low pON followed by an increase in particulate organic sulfate (pOS), and decrease in BF. Based on these observations, we hypothesize that acid-catalyzed hydrolysis of pON from IN- and MTN-derived SOA may be driving the transition of pON to pOS, leading to a change in the phase state of SOA. Preliminary results also indicate that the smallest particles can be acidic. We will further explore the role of LWC on the phase state of the particles applying ISORROPIA analysis. Although the PROPHET forest is generally NOx-limited, the work presented here highlights the potential importance of NOx and pON chemistry in dictating the phase state of SOA.

Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Satyender; Kumar, Vivek; Vashisht, Kapil

2011-11-15

Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activitymore » toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p < 0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37 {+-} 2.15 vs. 6.24 {+-} 1.37 tail% DNA, p < 0.001). Further, the workers with CYP2D6*3 PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p < 0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. -- Highlights: Black-Right-Pointing-Pointer Role of CYP1A1, CYP3A5, CYP2C, CYP2D6 and PON1 genotypes on DNA damage. Black-Right-Pointing-Pointer Workers exposed to some OPs demonstrated increased DNA damage. Black-Right-Pointing-Pointer CYP2D6 *3 PM and PON1 (Q192R and L55M) genotypes are associated with DNA damage. Black-Right-Pointing-Pointer Concomitant presence of certain CYP2D6 and PON1 genotypes can increase DNA damage.« less

A New Wavelength Optimization and Energy-Saving Scheme Based on Network Coding in Software-Defined WDM-PON Networks

NASA Astrophysics Data System (ADS)

Ren, Danping; Wu, Shanshan; Zhang, Lijing

2016-09-01

In view of the characteristics of the global control and flexible monitor of software-defined networks (SDN), we proposes a new optical access network architecture dedicated to Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) systems based on SDN. The network coding (NC) technology is also applied into this architecture to enhance the utilization of wavelength resource and reduce the costs of light source. Simulation results show that this scheme can optimize the throughput of the WDM-PON network, greatly reduce the system time delay and energy consumption.

Demonstration and field trial of a resilient hybrid NG-PON test-bed

NASA Astrophysics Data System (ADS)

Prat, Josep; Polo, Victor; Schrenk, Bernhard; Lazaro, Jose A.; Bonada, Francesc; Lopez, Eduardo T.; Omella, Mireia; Saliou, Fabienne; Le, Quang T.; Chanclou, Philippe; Leino, Dmitri; Soila, Risto; Spirou, Spiros; Costa, Liliana; Teixeira, Antonio; Tosi-Beleffi, Giorgio M.; Klonidis, Dimitrios; Tomkos, Ioannis

2014-10-01

A multi-layer next generation PON prototype has been built and tested, to show the feasibility of extended hybrid DWDM/TDM-XGPON FTTH networks with resilient optically-integrated ring-trees architecture, supporting broadband multimedia services. It constitutes a transparent common platform for the coexistence of multiple operators sharing the optical infrastructure of the central metro ring, passively combining the access and the metropolitan network sections. It features 32 wavelength connections at 10 Gbps, up to 1000 users distributed in 16 independent resilient sub-PONs over 100 km. This paper summarizes the network operation, demonstration and field trial results.

PON1-192 phenotype and genotype assessments in 918 subjects of the Stanislas cohort study.

PubMed

Vincent-Viry, Monique; Sass, Catherine; Bastien, Sabine; Aguillon, Dominique; Siest, Gérard; Visvikis, Sophie

2003-04-01

This study describes the factors of variation of the enzymes related to the PON1-192 phenotype assessment, i.e., basal paraoxonase, salt-stimulated paraoxonase and arylesterase activities, and compares the PON1-192 phenotype to the PON1-192 genotype assessments in supposedly healthy subjects issued from the Stanislas cohort study. The studied population included 918 subjects, i.e., 221 families including 441 adults and 477 children aged 4 to 58 years. Potential determinants such as age, gender, body mass index, alcohol and tobacco consumption, and oral contraceptive intake have been studied. The PON ratio (salt-stimulated paraoxonase/arylesterase) was trimodally distributed and the cut-off values used to differentiate the two homozygous (AA and BB phenotypes) from the heterozygous (AB phenotype) subjects were 3.0 and 7.0 in this study. In males, basal paraoxonase and salt-stimulated paraoxonase activities were not affected by alcohol consumption and current smoking, but basal paraoxonase activity was decreased by 15% by current smoking and was increased by 15% by oral contraceptive intake in females as was the salt-stimulated paraoxonase activity. The level of discordance between phenotype and genotype assessments was 7.2% (66/918). Most of the discrepancies were observed between the BB and AB phenotypes (4.25%).

Vasospastic angina and microvascular angina are differentially influenced by PON1 A632G polymorphism in the Japanese.

PubMed

Mashiba, Junko; Koike, George; Kamiunten, Hitoshi; Ikeda, Manami; Sunagawa, Kenji

2005-12-01

Ethnicity and smoking are well-known risk factors for the pathogenesis of coronary vasospasm. Oxidative stress induced by smoking plays a crucial role in coronary vasospasm, but is not enough to account for the pathogenesis of coronary vasospasm, indicating that genetic factors are strongly involved. The study group comprised 162 vasospastic angina patients (VSAs), 61 microvascular angina patients (MVAs) and 61 non-responders (NRs) diagnosed by acetylcholine provocation test. Four polymorphisms of the oxidative stress related genes, cytochrome b-245, alpha polypeptide gene (CYBA) C242T and A640G, paraoxonase 1 gene (PON1) A632G, phospholipase A2 group VII gene (PLA2G7) G994T were genotyped. Allele frequency of PON1 632-G was significantly higher in both the VSA with dominant fashion and the MVA with recessive fashion compared with NR. This association was strongly influenced by gender in the MVA only. There were no significant associations between the other polymorphisms and coronary vasospasm. In addition, the allele frequency of PON1 632-G in the Japanese was higher than in Caucasians. There was a significant association between PON1 A632G polymorphism and MVA as well as VSA, but the impact of this on VSA and MVA is different in the Japanese.

Low levels of serum paraoxonase activities are characteristic of metabolic syndrome and may influence the metabolic-syndrome-related risk of coronary artery disease.

PubMed

Martinelli, Nicola; Micaglio, Roberta; Consoli, Letizia; Guarini, Patrizia; Grison, Elisa; Pizzolo, Francesca; Friso, Simonetta; Trabetti, Elisabetta; Pignatti, Pier Franco; Corrocher, Roberto; Olivieri, Oliviero; Girelli, Domenico

2012-01-01

Low concentrations of plasma high-density lipoprotein (HDLs) are characteristic in metabolic syndrome (MS). The antioxidant ability of HDLs is, at least in part, attributable to pleiotropic serum paraoxonase (PON1). Different PON1 activities have been assessed in 293 subjects with (n = 88) or without MS (n = 205) and with (n = 195) or without (n = 98) angiographically proven coronary artery disease (CAD). MS subjects had low PON1 activities, with a progressively decreasing trend by increasing the number of MS abnormalities. The activity versus 7-O-diethyl phosphoryl,3-cyano,4-methyl,7-hydroxycoumarin (DEPCyMC), which is considered a surrogate marker of PON1 concentration, showed the most significant association with MS, independently of both HDL and apolipoprotein A-I levels. Subjects with MS and low DEPCyMCase activity had the highest CAD risk (OR 4.34 with 95% CI 1.44-13.10), while no significant increase of risk was found among those with MS but high DEPCyMCase activity (OR 1.45 with 95% CI 0.47-4.46). Our results suggest that low PON1 concentrations are typical in MS and may modulate the MS-related risk of CAD.

Low Levels of Serum Paraoxonase Activities are Characteristic of Metabolic Syndrome and May Influence the Metabolic-Syndrome-Related Risk of Coronary Artery Disease

PubMed Central

Martinelli, Nicola; Micaglio, Roberta; Consoli, Letizia; Guarini, Patrizia; Grison, Elisa; Pizzolo, Francesca; Friso, Simonetta; Trabetti, Elisabetta; Pignatti, Pier Franco; Corrocher, Roberto; Olivieri, Oliviero; Girelli, Domenico

2012-01-01

Low concentrations of plasma high-density lipoprotein (HDLs) are characteristic in metabolic syndrome (MS). The antioxidant ability of HDLs is, at least in part, attributable to pleiotropic serum paraoxonase (PON1). Different PON1 activities have been assessed in 293 subjects with (n = 88) or without MS (n = 205) and with (n = 195) or without (n = 98) angiographically proven coronary artery disease (CAD). MS subjects had low PON1 activities, with a progressively decreasing trend by increasing the number of MS abnormalities. The activity versus 7-O-diethyl phosphoryl,3-cyano,4-methyl,7-hydroxycoumarin (DEPCyMC), which is considered a surrogate marker of PON1 concentration, showed the most significant association with MS, independently of both HDL and apolipoprotein A-I levels. Subjects with MS and low DEPCyMCase activity had the highest CAD risk (OR 4.34 with 95% CI 1.44–13.10), while no significant increase of risk was found among those with MS but high DEPCyMCase activity (OR 1.45 with 95% CI 0.47–4.46). Our results suggest that low PON1 concentrations are typical in MS and may modulate the MS-related risk of CAD. PMID:21960992

Physically secured orthogonal frequency division multiplexing-passive optical network employing noise-based encryption and signal recovery process

NASA Astrophysics Data System (ADS)

Jin, Wei; Zhang, Chongfu; Yuan, Weicheng

2016-02-01

We propose a physically enhanced secure scheme for direct detection-orthogonal frequency division multiplexing-passive optical network (DD-OFDM-PON) and long reach coherent detection-orthogonal frequency division multiplexing-passive optical network (LRCO-OFDM-PON), by employing noise-based encryption and channel/phase estimation. The noise data generated by chaos mapping are used to substitute training sequences in preamble to realize channel estimation and frame synchronization, and also to be embedded on variable number of key-selected randomly spaced pilot subcarriers to implement phase estimation. Consequently, the information used for signal recovery is totally hidden as unpredictable noise information in OFDM frames to mask useful information and to prevent illegal users from correctly realizing OFDM demodulation, and thereby enhancing resistance to attackers. The levels of illegal-decryption complexity and implementation complexity are theoretically discussed. Through extensive simulations, the performances of the proposed channel/phase estimation and the security introduced by encrypted pilot carriers have been investigated in both DD-OFDM and LRCO-OFDM systems. In addition, in the proposed secure DD-OFDM/LRCO-OFDM PON models, both legal and illegal receiving scenarios have been considered. These results show that, by utilizing the proposed scheme, the resistance to attackers can be significantly enhanced in DD-OFDM-PON and LRCO-OFDM-PON systems without performance degradations.

An assessment of antioxidant status in patients with carbon monoxide poisoning

PubMed Central

Zengin, Suat; A, Behcet; Karta, Sahin; Can, Basri; Orkmez, Mustafa; Taskin, Abdullah; Lok, Ugur; Gulen, Bediha; Yildirim, Cuma; Taysi, Seyithan

2014-01-01

BACKGROUND: Carbon monoxide poisoning (COP) is an important cause of mortality and morbidity worldwide. This study was to investigate the levels of serum paraoxonase (PON), arylesterase (ARYL), ceruloplasmin (Cp), and sulfhydryl (-SH) in the treatment of COP, and to further understand the pathophysiology of COP. METHODS: This prospective study comprised 107 individuals with COP (group 1) and 50 healthy volunteers (group 2). Serum, plasma, and erythrocyte samples were taken on admission from all participants with COP. This process was repeated in the 90th and 180th minutes of treatment. Samples were taken from the control group only once. The levels of plasma PON, ARYL, Cp activity and -SH were measured in both groups. RESULTS: Age, gender, and carboxyhemoglobin level were not correlated with PON, ARYL, Cp, and -SH levels. PON, ARYL, and -SH levels were significantly decreased in group 1 compared with group 2. Conversely, Cp was significantly elevated in group 1 in contrast to group 2. Although ARYL was lower on admission in patients with COP than that was observed in the 90th and 180th minutes (P<0.001), Cp was higher on admission than at the other time points (P<0.001). CONCLUSIONS: Participants with COP had decreased levels of antioxidants (PON, ARLY, and -SH). COP represses the antioxidant system. PMID:25215155

Preserved pontine glucose metabolism in Alzheimer disease: A reference region for functional brain image (PET) analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minoshima, Satoshi; Frey, K.A.; Foster, N.L.

1995-07-01

Our goal was to examine regional preservation of energy metabolism in Alzheimer disease (AD) and to evaluate effects of PET data normalization to reference regions. Regional metabolic rates in the pons, thalamus, putamen, sensorimotor cortex, visual cortex, and cerebellum (reference regions) were determined stereotaxically and examined in 37 patients with probable AD and 22 normal controls based on quantitative {sup 18}FDG-PET measurements. Following normalization of metabolic rates of the parietotemporal association cortex and whole brain to each reference region, distinctions of the two groups were assessed. The pons showed the best preservation of glucose metabolism in AD. Other reference regionsmore » showed relatively preserved metabolism compared with the parietotemporal association cortex and whole brain, but had significant metabolic reduction. Data normalization to the pons not only enhanced statistical significance of metabolic reduction in the parietotemporal association cortex, but also preserved the presence of global cerebral metabolic reduction indicated in analysis of the quantitative data. Energy metabolism in the pons in probable AD is well preserved. The pons is a reliable reference for data normalization and will enhance diagnostic accuracy and efficiency of quantitative and nonquantitative functional brain imaging. 39 refs., 2 figs., 3 tabs.« less

Demonstration of digital fronthaul over self-seeded WDM-PON in commercial LTE environment.

PubMed

Ma, Yiran; Xu, Zhiguang; Zhang, Chengliang; Lin, Huafeng; Wang, Qing; Zhou, Min; Wang, Heng; Yu, Jingwen; Wang, Xiaomu

2015-05-04

CPRI between BBU and RRU equipment is carried by self-seeded WDM-PON prototype system within commercial LTE end-to-end environment. Delay and jitter meets CPRI requirements while services demonstrated show the same performance as bare fiber.

The Paraoxonase 1 Gene c.-108C>T SNP in the Promoter Is Associated with Risk for Glioma in Mexican Patients, but Not the p.L55M or p.Q192R Polymorphisms in the Coding Region.

PubMed

González-Herrera, Lizbeth; Gamas-Trujillo, Pablo Alejandro; Medina-Escobedo, Gilberto; Oaxaca-Castillo, David; Pérez-Mendoza, Gerardo; Williams-Jacquez, Dayana; Canto-Cetina, Thelma; Vargas-García, Rubén Darío

2015-09-01

To evaluate the association of the paraoxonase 1 (PON1) gene polymorphisms c.-108C>T, p.L55M, and p.Q192R with the risk of glioma in Southeast Mexico. Decreased PON1 activity caused by polymorphisms has been observed in gliomas, thus supporting the theory that PON1 is involved in tumorigenesis in the brain. Sixty-seven glioma patients and 58 control individuals were included. Three PON1 polymorphisms were genotyped by real-time PCR allelic discrimination using TaqMan probes: c.-108C>T in the promoter region, p.Q192R and p.L55M, both of which were in the coding region. Allele, genotype, and haplotype frequencies were assessed in cases and controls to test for statistical associations (STATA 10.2 package). Significant differences were found for the PON1 c.-108C>T polymorphism between the cases and controls. Compared to the controls the cases were more likely to be CT heterozygous (p =  0.002) or TT homozygous (p = 0.036); similarly cases were more likely to possess a T allele (p = 0.032). In contrast, the p.L55M and p.Q192R polymorphisms did not show significant differences between the glioma cases and controls (p > 0.05). The PON1 c.-108C>T polymorphism in the promoter region is associated with genetic risk for glioma. Conversely, p.L55M and p.Q192R polymorphisms in the coding region do not seem to have an influence in this population.

Collaborative video caching scheme over OFDM-based long-reach passive optical networks

NASA Astrophysics Data System (ADS)

Li, Yan; Dai, Shifang; Chang, Xiangmao

2018-07-01

Long-reach passive optical networks (LR-PONs) are now considered as a desirable access solution for cost-efficiently delivering broadband services by integrating metro network with access network, among which orthogonal frequency division multiplexing (OFDM)-based LR-PONs gain greater research interests due to their good robustness and high spectrum efficiency. In such attractive OFDM-based LR-PONs, however, it is still challenging to effectively provide video service, which is one of the most popular and profitable broadband services, for end users. Given that more video requesters (i.e., end users) far away from optical line terminal (OLT) are served in OFDM-based LR-PONs, it is efficiency-prohibitive to use traditional video delivery model, which relies on the OLT to transmit videos to requesters, for providing video service, due to the model will incur not only larger video playback delay but also higher downstream bandwidth consumption. In this paper, we propose a novel video caching scheme that to collaboratively cache videos on distributed optical network units (ONUs) which are closer to end users, and thus to timely and cost-efficiently provide videos for requesters by ONUs over OFDM-based LR-PONs. We firstly construct an OFDM-based LR-PON architecture to enable the cooperation among ONUs while caching videos. Given a limited storage capacity of each ONU, we then propose collaborative approaches to cache videos on ONUs with the aim to maximize the local video hit ratio (LVHR), i.e., the proportion of video requests that can be directly satisfied by ONUs, under diverse resources requirements and requests distributions of videos. Simulations are finally conducted to evaluate the efficiency of our proposed scheme.

Active Site Hydrophobicity and the Convergent Evolution of Paraoxonase Activity in Structurally Divergent Enzymes: The Case of Serum Paraoxonase 1

PubMed Central

2016-01-01

Serum paraoxonase 1 (PON1) is a native lactonase capable of promiscuously hydrolyzing a broad range of substrates, including organophosphates, esters, and carbonates. Structurally, PON1 is a six-bladed β-propeller with a flexible loop (residues 70–81) covering the active site. This loop contains a functionally critical Tyr at position 71. We have performed detailed experimental and computational analyses of the role of selected Y71 variants in the active site stability and catalytic activity in order to probe the role of Y71 in PON1’s lactonase and organophosphatase activities. We demonstrate that the impact of Y71 substitutions on PON1’s lactonase activity is minimal, whereas the kcat for the paraoxonase activity is negatively perturbed by up to 100-fold, suggesting greater mutational robustness of the native activity. Additionally, while these substitutions modulate PON1’s active site shape, volume, and loop flexibility, their largest effect is in altering the solvent accessibility of the active site by expanding the active site volume, allowing additional water molecules to enter. This effect is markedly more pronounced in the organophosphatase activity than the lactonase activity. Finally, a detailed comparison of PON1 to other organophosphatases demonstrates that either a similar “gating loop” or a highly buried solvent-excluding active site is a common feature of these enzymes. We therefore posit that modulating the active site hydrophobicity is a key element in facilitating the evolution of organophosphatase activity. This provides a concrete feature that can be utilized in the rational design of next-generation organophosphate hydrolases that are capable of selecting a specific reaction from a pool of viable substrates. PMID:28026940

Active Site Hydrophobicity and the Convergent Evolution of Paraoxonase Activity in Structurally Divergent Enzymes: The Case of Serum Paraoxonase 1.

PubMed

Blaha-Nelson, David; Krüger, Dennis M; Szeler, Klaudia; Ben-David, Moshe; Kamerlin, Shina Caroline Lynn

2017-01-25

Serum paraoxonase 1 (PON1) is a native lactonase capable of promiscuously hydrolyzing a broad range of substrates, including organophosphates, esters, and carbonates. Structurally, PON1 is a six-bladed β-propeller with a flexible loop (residues 70-81) covering the active site. This loop contains a functionally critical Tyr at position 71. We have performed detailed experimental and computational analyses of the role of selected Y71 variants in the active site stability and catalytic activity in order to probe the role of Y71 in PON1's lactonase and organophosphatase activities. We demonstrate that the impact of Y71 substitutions on PON1's lactonase activity is minimal, whereas the k cat for the paraoxonase activity is negatively perturbed by up to 100-fold, suggesting greater mutational robustness of the native activity. Additionally, while these substitutions modulate PON1's active site shape, volume, and loop flexibility, their largest effect is in altering the solvent accessibility of the active site by expanding the active site volume, allowing additional water molecules to enter. This effect is markedly more pronounced in the organophosphatase activity than the lactonase activity. Finally, a detailed comparison of PON1 to other organophosphatases demonstrates that either a similar "gating loop" or a highly buried solvent-excluding active site is a common feature of these enzymes. We therefore posit that modulating the active site hydrophobicity is a key element in facilitating the evolution of organophosphatase activity. This provides a concrete feature that can be utilized in the rational design of next-generation organophosphate hydrolases that are capable of selecting a specific reaction from a pool of viable substrates.

Intravenous injection of gadobutrol in an epidemiological study group did not lead to a difference in relative signal intensities of certain brain structures after 5 years.

PubMed

Kromrey, Marie-Luise; Liedtke, Kim Rouven; Ittermann, Till; Langner, Sönke; Kirsch, Michael; Weitschies, Werner; Kühn, Jens-Peter

2017-02-01

To investigate if application of macrocyclic gadolinium-based contrast agents in volunteers is associated with neuronal deposition detected by magnetic resonance imaging in a 5-year longitudinal survey. Three hundred eighty-seven volunteers who participated in a population-based study were enrolled. Subjects underwent plain T1-weighted brain MRI at baseline and 5 years later with identical sequence parameters. At baseline, 271 participants additionally received intravenous injection of the macrocyclic contrast agent gadobutrol (0.15 mmol/kg). A control group including 116 subjects received no contrast agent. Relative signal intensities of thalamus, pallidum, pons and dentate nucleus were compared at baseline and follow-up. No difference in relative signal intensities was observed between contrast group (thalamus, p = 0.865; pallidum, p = 0.263; pons, p = 0.533; dentate nucleus, p = 0.396) and control group (thalamus, p = 0.683; pallidum; p = 0.970; pons, p = 0.773; dentate nucleus, p = 0.232) at both times. Comparison between both groups revealed no significant differences in relative signal intensities (thalamus, p = 0.413; pallidum, p = 0.653; pons, p = 0.460; dentate nucleus, p = 0.751). The study showed no significant change in globus pallidus-to-thalamus or dentate nucleus-to-pons ratios. Five years after administration of a 1.5-fold dose gadobutrol to normal subjects, signal intensity of thalamus, pallidum, pons and dentate nucleus did not differ from participants who had not received gadobutrol. • Gadobutrol does not lead to neuronal signal alterations after 5 years. • Neuronal deposition of macrocyclic contrast agent could not be confirmed. • Macrocyclic contrast agents in a proven dosage are safe.

A small pons as a characteristic finding in Down syndrome: A quantitative MRI study.

PubMed

Fujii, Yuta; Aida, Noriko; Niwa, Tetsu; Enokizono, Mikako; Nozawa, Kumiko; Inoue, Tomio

2017-04-01

Down syndrome (DS) is the most common chromosomal aberration, but the characteristics of the brainstem component in this condition during childhood (from newborn to preteen stages) have not been clarified. To evaluate the morphological features of the brainstem in DS on magnetic resonance imaging (MRI). MRIs for 32 children with DS (16 boys and girls each; age range, 0-11years) without major brain insults, and 32 age-matched controls (16 boys and girls each) were retrospectively analyzed. Height, width, and area of the midbrain, pons, and medulla oblongata were measured on sagittal T1-weighted images; these were compared in children with DS and age-matched controls. The ratios of the brainstem to the size of the posterior fossa (BS/PF index) were calculated; these were also compared in the children with DS and the control group. The width and area of the midbrain; height, width, area of the pons; and area of the medulla oblongata were significantly smaller in children with DS than in control children (P<0.05); the area of the pons, particularly for the ventral part, showed the largest differences in the mean relative differences. The BS/PF indices of the height, width, and area of the pons were significantly smaller in children with DS than in the control group (P<0.01). However, the BS/PF indices for the midbrain and the medulla oblongata did not differ between these two groups. Children with DS may have small brainstems, particularly in the pons; this may be a characteristic morphological feature of the brainstem on MRI in childhood including neonates. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

R-carrying genotypes of serum paraoxonase (PON1) 192 polymorphism and higher activity ratio are related to susceptibility against ischemic stroke.

PubMed

Mahrooz, Abdolkarim; Gohari, Ghorban; Hashemi, Mohammad-Bagher; Zargari, Mehryar; Musavi, Hadis; Abedini, Mahmoud; Alizadeh, Ahad

2012-12-01

The polymorphic gene of serum paraoxonase (PON1) and its activity involved in atherosclerosis. The purpose of the study was to analyze PON1 192 Q/R polymorphism and the enzyme activities in ischemic stroke. The polymorphism as the most common polymorphism in PON1 gene coding sequence is associated with variation in the enzyme activity and vascular disease. The study included 85 stroke patients and 71 control subjects. PON1 192 polymorphism was genotyped using PCR protocol. Paraoxonase activity (Para) and arylesterase activity (Aryl) were determined spectrophotometrically using paraoxon and phenylacetate as the substrates. The QR and RR genotypes were more frequent in stroke population compared to controls, resulting in a higher frequency of the R allele in patients (0.24 vs 0.18, OR = 1.41). Patients had significantly higher Para/Aryl ratio than that of controls (P = 0.016). In stroke patients, Para/Aryl and Para/HDL ratios increased with this order: QQ < QR < RR. Hypertension significantly increased the risk of ischemic stroke by 15-fold among R-containing people, while this was significantly increased 4-fold for QQ homozygotes. Smoking increased the risk of having ischemic stroke in both QQ homozygote and QR + RR group (OR = 2.84 and OR = 2.33, respectively). In conclusion, these data highlight the importance of PON1 192 R allele and high Para/Aryl ratio in susceptibility to ischemic stroke in the population. The presence of the 192 R allele potentiates the risk of stroke especially in hypertensive people. Decreased Aryl and increased Para/Aryl, Para/HDL and Aryl/HDL ratios may be markers indicated the increased susceptibility to ischemic stroke in the population.

Association of paraoxonase-1 gene polymorphisms with insulin resistance in South Indian population.

PubMed

Gomathi, Panneerselvam; Iyer, Anandi Chandramouli; Murugan, Ponniah Senthil; Sasikumar, Sundaresan; Raj, Nancy Bright Arul Joseph; Ganesan, Divya; Nallaperumal, Sivagnanam; Murugan, Maruthamuthu; Selvam, Govindan Sadasivam

2018-04-15

Insulin resistance plays a crucial role in the pathogenesis of type 2 diabetes and cardiovascular diseases. Recently, paraoxonase-1(PON1) is reported to have an ability to reduce insulin resistance by promoting glucose transporter-4 (GLUT-4) expression in vitro. Single nucleotide polymorphism (SNP) in PON1 is associated with variability in enzyme activity and concentration. Based on this we aimed to investigate the association of PON1 (Q192R and L55M) polymorphisms with the risk of developing insulin resistance in adult South Indian population. Two hundred and eighty seven (287) Type 2 diabetes patients and 293 healthy controls were enrolled in this study. All the study subjects were genotyped for PON1 (Q192R and L55M) missense polymorphisms using polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) method. Fasting serum insulin level was measured by ELISA. The distribution of QR/RR and LM/MM genotypes were significantly higher in type 2 diabetes patients compared with healthy controls. Moreover, the R and M alleles were significantly associated with type 2 diabetes with an Odds Ratio of 1.68 (P < 0.005) and 2.24 (P < 0.005) respectively. SNP 192 Q > R genotypes were found to be significantly associated with higher BMI, cholesterol, triglycerides, LDL, fasting serum insulin and HOMA-IR. Further, the mutant allele or genotypes of PON1 L55M were associated with higher BMI, triglycerides, VLDL, fasting serum insulin and HOMA-IR among adult type 2 diabetes patients. PON1 (Q192R and L55M) polymorphisms may play a crucial role in pathogenesis and susceptibility of insulin resistance thus leads to the development of type 2 diabetes in South Indian population. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of soy bean on serum paraoxonase 1 activity and lipoproteins in hyperlipidemic postmenopausal women.

PubMed

Shidfar, Farzad; Ehramphosh, Elham; Heydari, Iraj; Haghighi, Ladan; Hosseini, Sharieh; Shidfar, Shahrzad

2009-05-01

Because of an unfavorable serum lipoprotein profile, postmenopausal women are at risk of cardiovascular disease. Soy protein may help protect against these risk factors, although its effect on paraoxonase 1 (PON1) is not clear. The aim of the present study was to determine the effects of soy protein on serum concentration of lipoproteins and PON1 activity in hypercholesterolemic postmenopausal women. In a double-blind randomized clinical trial with a parallel design, 52 hypercholesterolemic postmenopausal women were randomly assigned to 50 g/day soy protein containing 164 mg isoflavones or placebo, for 10 weeks. Serum lipoproteins and PON1 activity were measured at baseline and at the 10th week. There was significant increase in PON1 activity (P=0.029) and a significant decrease in low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), LDL-C/high-density lipoprotein cholesterol (HDL-C), triacylglycerol/HDL-C and TC/HDL-C in the soy group compared with the placebo group (P=0.001, P=0.008, P=0.012, P=0.04 and P=0.029, respectively) at the end of the study. Similarly, PON1 activity was significantly increased (P=0.015) and LDL-C, TC, LDL-C/HDL-C, triacylglycerol/HDL-C and TC/HDL-C were significantly decreased (P=0.001, P=0.002, P=0.001, P=0.016 and P=0.001) at the end of the study compared with the beginning value in soy group. Soy protein reduces the cardiovascular disease risk in postmenopausal women because of both modest reductions in serum lipoproteins and an increase in PON1 activity.

Effect of short-term, high-dose methylprednisolone on oxidative stress in children with acute immune thrombocytopenia.

PubMed

Cura, Musa; Koç, Ahmet; Aksoy, Nurten; Özdemir, Zeynep Canan

2016-12-01

Immune thrombocytopenia (ITP) is the most common cause of acquired childhood thrombocytopenia and is characterized by increased immune-mediated destruction of circulating thrombocytes. Oxidative damage may be involved in ITP pathogenesis; paraoxonase (PON) and arylesterase (ARE) enzymes are closely associated with the cellular antioxidant system. We investigated the effect of short-term high-dose methylprednisolone (HDMP) treatment on the total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), and PON and ARE enzymatic activity in children with acute ITP. Thirty children with acute ITP constituted the study group and 30 healthy children constituted the control group. Children with acute ITP were treated with HDMP: 30 mg/kg for 3 days, then 20 mg/kg for 4 days. The TOS, TAC, OSI, PON, and ARE levels were determined before and after 7 days of HDMP treatment. The TAC level ( P <0.001), and PON ( P <0.001) and ARE (P=0.001) activities were lower and the TOS ( P =0.003) and OSI ( P <0.001) levels were higher in children with acute ITP than those in healthy children in the control group. We also observed statistically significant increases in the TAC ( P <0.01), PON ( P <0.001) and ARE levels ( P =0.001) and decreases in the TOS ( P <0.05) and OSI levels ( P <0.05) with 7 days of HDMP treatment compared to their values before treatment. Our study demonstrated increased oxidative stress (OSI and TOC) and decreased antioxidant capacity (TAC), PON, and ARE in ITP patients and that steroid treatment could be effective in reducing the oxidative stress.

Diffusion tensor imaging for anatomical localization of cranial nerves and cranial nerve nuclei in pontine lesions: initial experiences with 3T-MRI.

PubMed

Ulrich, Nils H; Ahmadli, Uzeyir; Woernle, Christoph M; Alzarhani, Yahea A; Bertalanffy, Helmut; Kollias, Spyros S

2014-11-01

With continuous refinement of neurosurgical techniques and higher resolution in neuroimaging, the management of pontine lesions is constantly improving. Among pontine structures with vital functions that are at risk of being damaged by surgical manipulation, cranial nerves (CN) and cranial nerve nuclei (CNN) such as CN V, VI, and VII are critical. Pre-operative localization of the intrapontine course of CN and CNN should be beneficial for surgical outcomes. Our objective was to accurately localize CN and CNN in patients with intra-axial lesions in the pons using diffusion tensor imaging (DTI) and estimate its input in surgical planning for avoiding unintended loss of their function during surgery. DTI of the pons obtained pre-operatively on a 3Tesla MR scanner was analyzed prospectively for the accurate localization of CN and CNN V, VI and VII in seven patients with intra-axial lesions in the pons. Anatomical sections in the pons were used to estimate abnormalities on color-coded fractional anisotropy maps. Imaging abnormalities were correlated with CN symptoms before and after surgery. The course of CN and the area of CNN were identified using DTI pre- and post-operatively. Clinical associations between post-operative improvements and the corresponding CN area of the pons were demonstrated. Our results suggest that pre- and post-operative DTI allows identification of key anatomical structures in the pons and enables estimation of their involvement by pathology. It may predict clinical outcome and help us to better understand the involvement of the intrinsic anatomy by pathological processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

An economic analysis on optical Ethernet in the access network

NASA Astrophysics Data System (ADS)

Kim, Sung Hwi; Nam, Dohyun; Yoo, Gunil; Kim, WoonHa

2004-04-01

Nowadays, Broadband service subscribers have increased exponentially and have almost saturated in Korea. Several types of solutions for broadband service applied to the field. Among several types of broadband services, most of subscribers provided xDSL service like ADSL or VDSL. Usually, they who live in an apartment provided Internet service by Ntopia network as FTTC structure that is a dormant network in economical view at KT. Under competitive telecom environment for new services like video, we faced with needing to expand or rebuild portions of our access networks, are looking for ways to provide any service that competitors might offer presently or in the near future. In order to look for new business model like FTTH service, we consider deploying optical access network. In spite of numerous benefits of PON until now, we cannot believe that PON is the best solution in Korea. Because we already deployed optical access network of ring type feeder cable and have densely population of subscribers that mainly distributed inside 6km from central office. So we try to utilize an existing Ntopia network for FTTH service under optical access environment. Despite of such situations, we try to deploy PON solution in the field as FTTC or FTTH architecture. Therefore we analyze PON structure in comparison with AON structure in order to look for optimized structure in Korea. At first, we describe the existing optical access networks and network architecture briefly. Secondly we investigate the cost of building optical access networks by modeling cost functions on AON and PON structure which based on Ethernet protocol, and analyze two different network architectures according to different deployment scenarios: Urban, small town, rural. Finally we suggest the economic and best solution with PON structure to optimize to optical access environment of KT.

PONS2train: tool for testing the MLP architecture and local traning methods for runoff forecast

NASA Astrophysics Data System (ADS)

Maca, P.; Pavlasek, J.; Pech, P.

2012-04-01

The purpose of presented poster is to introduce the PONS2train developed for runoff prediction via multilayer perceptron - MLP. The software application enables the implementation of 12 different MLP's transfer functions, comparison of 9 local training algorithms and finally the evaluation the MLP performance via 17 selected model evaluation metrics. The PONS2train software is written in C++ programing language. Its implementation consists of 4 classes. The NEURAL_NET and NEURON classes implement the MLP, the CRITERIA class estimates model evaluation metrics and for model performance evaluation via testing and validation datasets. The DATA_PATTERN class prepares the validation, testing and calibration datasets. The software application uses the LAPACK, BLAS and ARMADILLO C++ linear algebra libraries. The PONS2train implements the first order local optimization algorithms: standard on-line and batch back-propagation with learning rate combined with momentum and its variants with the regularization term, Rprop and standard batch back-propagation with variable momentum and learning rate. The second order local training algorithms represents: the Levenberg-Marquardt algorithm with and without regularization and four variants of scaled conjugate gradients. The other important PONS2train features are: the multi-run, the weight saturation control, early stopping of trainings, and the MLP weights analysis. The weights initialization is done via two different methods: random sampling from uniform distribution on open interval or Nguyen Widrow method. The data patterns can be transformed via linear and nonlinear transformation. The runoff forecast case study focuses on PONS2train implementation and shows the different aspects of the MLP training, the MLP architecture estimation, the neural network weights analysis and model uncertainty estimation.

Differential effect of mutational impairment of penicillin-binding proteins 1A and 1B on Escherichia coli strains harboring thermosensitive mutations in the cell division genes ftsA, ftsQ, ftsZ, and pbpB.

PubMed Central

García del Portillo, F; de Pedro, M A

1990-01-01

To study the functional differences between penicillin-binding proteins (PBPs) 1A and 1B, as well as their recently postulated involvement in the septation process (F. García del Portillo, M. A. de Pedro, D. Joseleau-Petit, and R. D'Ari, J. Bacteriol. 171:4217-4221, 1989), a series of isogenic strains with mutations in the genes coding for PBP 1A (ponA) or PBP 1B (ponB) or in the cell division-specific genes ftsA, ftsQ, pbpB, and ftsZ was constructed and used as the start point to produce double mutants combining the ponA or ponB characters with mutations in cell division genes. PBP 1A seemed to be unable to preserve cell integrity by itself, requiring the additional activities of PBP 2, PBP 3, and FtsQ. PBP 1B was apparently endowed with a more versatile biosynthetic potential that permitted a substantial enlargement of PBP 1A-deficient cells when PBP 2 or 3 was inhibited or when FtsQ was inactive. beta-Lactams binding to PBP 2 (mecillinam) or 3 (furazlocillin) caused rapid lysis in a ponB background. The lytic effect of furazlocillin to ponB cell division double mutants was suppressed at the restrictive temperature irrespective of the identity of the mutated cell division gene. These results indicate that PBPs 1A and 1B play distinct roles in cell wall synthesis and support the idea of a relevant involvement of PBP 1B in peptidoglycan synthesis at the time of septation. Images PMID:2211517

Postnatal growth of the human pons: a morphometric and immunohistochemical analysis.

PubMed

Tate, Matthew C; Lindquist, Robert A; Nguyen, Thuhien; Sanai, Nader; Barkovich, A James; Huang, Eric J; Rowitch, David H; Alvarez-Buylla, Arturo

2015-02-15

Despite its critical importance to global brain function, the postnatal development of the human pons remains poorly understood. In the present study, we first performed magnetic resonance imaging (MRI)-based morphometric analyses of the postnatal human pons (0-18 years; n = 6-14/timepoint). Pons volume increased 6-fold from birth to 5 years, followed by continued slower growth throughout childhood. The observed growth was primarily due to expansion of the basis pontis. T2-based MRI analysis suggests that this growth is linked to increased myelination, and histological analysis of myelin basic protein in human postmortem specimens confirmed a dramatic increase in myelination during infancy. Analysis of cellular proliferation revealed many Ki67(+) cells during the first 7 months of life, particularly during the first month, where proliferation was increased in the basis relative to tegmentum. The majority of proliferative cells in the postnatal pons expressed the transcription factor Olig2, suggesting an oligodendrocyte lineage. The proportion of proliferating cells that were Olig2(+) was similar through the first 7 months of life and between basis and tegmentum. The number of Ki67(+) cells declined dramatically from birth to 7 months and further decreased by 3 years, with a small number of Ki67(+) cells observed throughout childhood. In addition, two populations of vimentin/nestin-expressing cells were identified: a dorsal group near the ventricular surface, which persists throughout childhood, and a parenchymal population that diminishes by 7 months and was not evident later in childhood. Together, our data reveal remarkable postnatal growth in the ventral pons, particularly during infancy when cells are most proliferative and myelination increases. © 2014 Wiley Periodicals, Inc.

Daily supplementation with fresh pomegranate juice increases paraoxonase 1 expression and activity in mice fed a high-fat diet.

PubMed

Estrada-Luna, D; Martínez-Hinojosa, E; Cancino-Diaz, J C; Belefant-Miller, H; López-Rodríguez, G; Betanzos-Cabrera, G

2018-02-01

Studies have found that pomegranate juice (PJ) consumption increases the binding of high-density lipoproteins (HDL) to paraoxonase 1 (PON1), thus increasing the catalytic activity of this enzyme. PON1 is an antioxidant arylesterase synthesized in the liver and transported in plasma in association with HDL. Decreased levels of PON1 are associated with higher levels of cholesterol. We determined the effects of PJ on body weight, cholesterol, and triacylglycerols through 5 months of supplementation. In addition, the effect of PJ on pon1 gene expression in the liver was also measured by RT-qPCR as well as the activity in serum by a semiautomated method using paraoxon as a substrate. CD-1 mice were either fed a control diet or were fed a high-fat diet 1.25% (wt/wt) cholesterol, 0.5% (wt/wt) sodium cholate, and 15% (wt/wt) saturated fat. 300 μL of PJ containing 0.35 mmol total polyphenols was administered by oral gavage to half of the high fat mice daily. The rest of the high fat mice and the control mice were administered with 300 μL of water. PJ-supplemented animals had significantly higher levels of expression of pon1 compared to the unsupplemented group. PJ-supplemented animals had twice the PON1 activity of the unsupplemented group. In addition, PJ-supplemented animals had the lowest body weight and significantly reduced cholesterol and triacylglycerol levels, although the tricylglycerol levels were not consistently decreased. These results suggest that PJ protects against the effects of a high-fat diet in body weight, and cholesterol levels.

A reconfigurable all-optical VPN based on XGM effect of SOA in WDM PON

NASA Astrophysics Data System (ADS)

Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Tao; Su, Yikai

2010-12-01

We propose and experimentally demonstrate a reconfigurable all-optical VPN scheme enabling intercommunications among different ONUs in a WDM PON. Reconfiguration is realized by dynamically setting wavelength conversion of optical VPN signal using a SOA in the OLT.

Remote coding scheme based on waveguide Bragg grating in PLC splitter chip for PON monitoring.

PubMed

Zhang, Xuan; Lu, Fengjun; Chen, Si; Zhao, Xingqun; Zhu, Min; Sun, Xiaohan

2016-03-07

A distributing arranged waveguide Bragg gratings (WBGs) in PLC splitter chip based remote coding scheme is proposed and analyzed for passive optical network (PON) monitoring, by which the management system can identify each drop fiber link through the same reflector in the terminal of each optical network unit, even though there exist several equidistant users. The corresponding coding and capacity models are respectively established and investigated so that we can obtain a minimum number of the WBGs needed under the condition of the distributed structure. Signal-to-noise ratio (SNR) model related to the number of equidistant users is also developed to extend the analyses for the overall performance of the system. Simulation results show the proposed scheme is feasible and allow the monitoring of a 64 users PON with SNR range of 7.5~10.6dB. The scheme can solve some of difficulties of construction site at the lower user cost for PON system.

Dynamic Bandwidth Allocation with Effective Utilization of Polling Interval over WDM/TDM PON

NASA Astrophysics Data System (ADS)

Ni, Cuiping; Gan, Chaoqin; Gao, Ziyue

2014-12-01

WDM/TDM (wavelength-division multiplexing/time-division multiplexing) PON (passive optical network) appears to be an attractive solution for the next generation optical access networks. Dynamic bandwidth allocation (DBA) plays a crucial role in efficiently and fairly allocating the bandwidth among all users in WDM/TDM PON. In this paper, two dynamic bandwidth allocation schemes (DBA1 and DBA2) are proposed to eliminate the idle time of polling cycles (i.e. polling interval), improve bandwidth utilization and make full use of bandwidth resources. The two DBA schemes adjust the time slot of sending request information and make fair scheduling among users to achieve the effective utilization of polling interval in WDM/TDM PON. The simulation and theoretical analyses verify that the proposed schemes outperform the conventional DBA scheme. We also make comparisons between the two schemes in terms of bandwidth utilization and average packet delay to further demonstrate the effectiveness of the scheme of DBA2.

Mechanical measurements on lithium phosphorous oxynitride coated silicon thin film electrodes for lithium-ion batteries during lithiation and delithiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Obeidi, Ahmed, E-mail: alobeidi@mit.edu; Thompson, Carl V., E-mail: reiner.moenig@kit.edu, E-mail: cthomp@mit.edu; Kramer, Dominik, E-mail: dominik.kramer@kit.edu

2016-08-15

The development of large stresses during lithiation and delithiation drives mechanical and chemical degradation processes (cracking and electrolyte decomposition) in thin film silicon anodes that complicate the study of normal electrochemical and mechanical processes. To reduce these effects, lithium phosphorous oxynitride (LiPON) coatings were applied to silicon thin film electrodes. Applying a LiPON coating has two purposes. First, the coating acts as a stable artificial solid electrolyte interphase. Second, it limits mechanical degradation by retaining the electrode's planar morphology during cycling. The development of stress in LiPON-coated electrodes was monitored using substrate curvature measurements. LiPON-coated electrodes displayed highly reproducible cycle-to-cyclemore » behavior, unlike uncoated electrodes which had poorer coulombic efficiency and exhibited a continual loss in stress magnitude with continued cycling due to film fracture. The improved mechanical stability of the coated silicon electrodes allowed for a better investigation of rate effects and variations of mechanical properties during electrochemical cycling.« less

Security scheme in IMDD-OFDM-PON system with the chaotic pilot interval and scrambling

NASA Astrophysics Data System (ADS)

Chen, Qianghua; Bi, Meihua; Fu, Xiaosong; Lu, Yang; Zeng, Ran; Yang, Guowei; Yang, Xuelin; Xiao, Shilin

2018-01-01

In this paper, a random chaotic pilot interval and permutations scheme without any requirement of redundant sideband information is firstly proposed for the physical layer security-enhanced intensity modulation direct detection orthogonal frequency division multiplexing passive optical network (IMDD-OFDM-PON) system. With the help of the position feature of inserting the pilot, a simple logistic chaos map is used to generate the random pilot interval and scramble the chaotic subcarrier allocation of each column pilot data for improving the physical layer confidentiality. Due to the dynamic chaotic permutations of pilot data, the enhanced key space of ∼103303 is achieved in OFDM-PON. Moreover, the transmission experiment of 10-Gb/s 16-QAM encrypted OFDM data is successfully demonstrated over 20-km single-mode fiber, which indicates that the proposed scheme not only improves the system security, but also can achieve the same performance as in the common IMDD-OFDM-PON system without encryption scheme.

Preferentially Oriented Ag Nanocrystals with Extremely High Activity and Faradaic Efficiency for CO2 Electrochemical Reduction to CO.

PubMed

Peng, Xiong; Karakalos, Stavros G; Mustain, William E

2018-01-17

Selective electrochemical reduction of CO 2 is one of the most important processes to study because of its promise to convert this greenhouse gas to value-added chemicals at low cost. In this work, a simple anodization treatment was devised that first oxidizes Ag to Ag 2 CO 3 , then uses rapid electrochemical reduction to create preferentially oriented nanoparticles (PONs) of metallic Ag (PON-Ag) with high surface area as well as high activity and very high selectivity for the reduction of CO 2 to CO. The PON-Ag catalyst was dominated by (110) and (100) orientation, which allowed PON-Ag to achieve a CO Faradaic efficiency of 96.7% at an operating potential of -0.69 V vs RHE. This performance is not only significantly higher than that of polycrystalline Ag (60% at -0.87 V vs RHE) but also represents one of the best combinations of activity and selectivity achieved to date - all with a very simple, scalable approach to electrode fabrication.

A cost-effective WDM-PON architecture simultaneously supporting wired, wireless and optical VPN services

NASA Astrophysics Data System (ADS)

Wu, Yanzhi; Ye, Tong; Zhang, Liang; Hu, Xiaofeng; Li, Xinwan; Su, Yikai

2011-03-01

It is believed that next-generation passive optical networks (PONs) are required to provide flexible and various services to users in a cost-effective way. To address this issue, for the first time, this paper proposes and demonstrates a novel wavelength-division-multiplexed PON (WDM-PON) architecture to simultaneously support three types of services: 1) wireless access traffic, 2) optical virtual passive network (VPN) communications, and 3) conventional wired services. In the optical line terminal (OLT), we use two cascaded Mach-Zehnder modulators (MZMs) on each wavelength channel to generate an optical carrier, and produce the wireless and the downstream traffic using the orthogonal modulation technique. In each optical network unit (ONU), the obtained optical carrier is modulated by a single MZM to provide the VPN and upstream communications. Consequently, the light sources in the ONUs are saved and the system cost is reduced. The feasibility of our proposal is experimentally and numerically verified.

Strawberries Added to the Usual Diet Suppress Fasting Plasma Paraoxonase Activity and Have a Weak Transient Decreasing Effect on Cholesterol Levels in Healthy Nonobese Subjects.

PubMed

Zasowska-Nowak, Anna; Nowak, Piotr J; Bialasiewicz, Piotr; Prymont-Przyminska, Anna; Zwolinska, Anna; Sarniak, Agata; Wlodarczyk, Anna; Markowski, Jaroslaw; Rutkowski, Krzysztof P; Nowak, Dariusz

2016-07-01

Strawberries can improve oxidants-antioxidants balance and reduce some cardiovascular risk factors in obese subjects. Paraoxonase-1 (PON-1) is a high-density lipoprotein-associated enzyme with antioxidant properties that can protect from coronary artery disease in humans. We examined the effect of strawberry consumption on plasma PON-1 activity and lipid profile in healthy nonobese subjects. Thirty-one subjects (body mass index [BMI] 24.4 ± 4.0 kg/m(2)) on their usual diet consumed 500 g of strawberry pulp daily for 30 days (first course) and after a 10-day washout the cycle was repeated (second course). Fasting blood and spot morning urine samples were collected before, during, and after each strawberry course (8 time points) for determination of paraoxonase and arylesterase PON-1 activities and lipid profile. Twenty subjects served as controls with respect to cholesterol and PON-1 activities changes over the study period. Strawberries decreased mean plasma paraoxonase PON-1 activity and this effect was more evident after the second course (by 11.6%, p < 0.05) than after the first course (5.4%, p = 0.06), whereas arylesterase activity was constant. Strawberries altered total cholesterol levels (p < 0.05) with a tendency to transiently decrease it (by 5.1%) only after 15 days of the first course. Triglycerides and high- and low-density lipoprotein cholesterol did not change in response to fruit consumption. No changes in PON-1 activities and lipid profile were noted in controls. Paraoxonase correlated with arylesterase activity (ƿ from 0.33 to 0.46 at the first 7 time points, p < 0.05). This association disappeared at the end of study (ƿ = 0.07) when the strongest inhibition of paraoxonase was noted. Supplementation of the usual diet with strawberries decreased paraoxonase PON-1 activity and did not improve lipid profiles in healthy nonobese subjects. Further studies are necessary to establish the clinical significance of paraoxonase suppression and to define a group of healthy subjects who can benefit from strawberry consumption with respect to cholesterol levels.

Paraoxonase (PON1) polymorphism and activity as the determinants of sensitivity to organophosphates in human subjects.

PubMed

Sirivarasai, Jintana; Kaojarern, Sming; Yoovathaworn, Krongtong; Sura, Thanyachai

2007-07-20

Paraoxonase (PON1) plays an important role in mechanism of organophosphorus compound (OP) toxicity, as seen both in vitro and in vivo studies. Polymorphisms of PON1 gene at coding and promoter regions have also been to affect on the hydrolytic activity and PON1 level. The objectives of this study were to determine PON1 polymorphism and activity in an OP-exposed population and the effects on inhibition of cholinesterase activity. The studied population consisted of control (n=30) and exposed groups (n=90). All enzyme activities (AChE, BuChE, paraoxonase, arylesterase and diazonase) were measured once for control group and two periods of exposure for exposed group. Three polymorphisms of PON1 (Q192R, L55M and T-108C) were identified only in the exposed subjects. The results demonstrated that AChE activity in both high (345.5 microkat/gHb) and low exposure periods (496.9 microkat/gHb) of the exposed group were significantly different from control group (649.7 microkat/gHb, p<0.01). For BuChE activity, the exposed group also showed the statistically lower level in both periods (high exposure period: 62.17 microkat/L and low exposure period: 81.84 microkat/L) than those in the control group (93.35 microkat/L). Serum paraoxonase activity was significantly different among individual genotypes, RR>QR>RR, LL>LM and -108CC>-108CT>-108TT, but this was not found for those of arylesterase and diazonase activities. Q192R and L55M as well as Q192R and T-108C also presented substantial linkage disequilibrium. Further analysis was performed with haplotypes and various enzyme activities. AChE activity was not affected by haplotypes. Individuals with "211" haplotype showed significantly higher paraoxonase activity and BuChE activity than other haplotypes but not in diazonase activity. In conclusion, PON1 gene exhibited a wide variation in enzyme activities both within and between genotypes which implied insights of a potentially difference in sensitivity to OP toxicity.

Distribution of PON1 polymorphisms PON1Q192R and PON1L55M among Chinese, Malay and Indian males in Singapore and possible susceptibility to organophosphate exposure.

PubMed

Chia, Sin Eng; Mohamed Ali, Safiyya; Yap, Peng Huat Eric; Gan, Linda; Ong, Yeong Bing; Chia, Kee Seng

2009-03-01

Organophosphate (OP)-containing pesticides are widely used worldwide for domestic and industrial purposes. Studies on acute and chronic exposure to OPs have revealed numerous health effects attributed mainly to acetylcholinesterase (AChE) inhibition. The enzyme human serum paraoxonase (PON1) is involved in the detoxification of OP compounds. PON1 polymorphisms have been shown to affect susceptibility to OP exposure. We studied the effect of OP exposure on pest control workers and assessed the distribution of two common PON1 polymorphisms in our local population. The exposed group consisted of 103 workers from various pest control companies under the Singapore Pest Management Association while the 91 unexposed workers were from a lead stabilizer factory. For all workers, the mean age was 36.9 (20-70) years and the ethnic distribution was 38.1% Chinese, 44.3% Malay and 17.5% Indian. The mean+/-S.D. exposure duration among the pesticide workers was 10.4+/-8.4 years. The mean+/-S.D. RBC cholinesterase level was 18436.2+/-2078U/L and 18079.6+/-1576U/L for the exposed and unexposed groups, respectively (p=0.216). The mean+/-S.D. serum pseudocholinesterase was 11028.4+/-2867.4U/L and 9433.6+/-2022.6U/L in the exposed and unexposed groups, respectively (p<0.0001). Mean paraoxonase activity was similar among Chinese and Malays (266.5 and 266.3U/L, respectively) whereas that of the Indians was significantly lower (165.6U/L). Our study showed that cholinesterase levels among the exposed were not lower than those in the unexposed group. PON1 polymorphisms differed among ethnic groups, implying that ethnicity could be an important surrogate for identifying susceptible groups in case of OP exposure. Although OP poisoning is rare among occupationally exposed workers in Singapore, this information is useful for other developing countries that have large populations of Chinese, Malays and Indians where OP exposure could be very high especially in agricultural settings.

Effects of Modulation Techniques (Manchester Code, NRZ or RZ) on the Operation of Hybrid WDM/TDM Passive Optical Networks

PubMed Central

Nyachionjeka, Kumbirayi

2014-01-01

In this paper, the performance and feasibility of a hybrid wavelength division multiplexing/time division multiplexing passive optical network (WDM/TDM PON) system with 128 optical network units (ONUs) is analysed. In this system, triple play services (video, voice and data) are successfully communicated through a distance of up to 28 km. Moreover, we analysed and compared the performance of various modulation formats for different distances in the proposed hybrid WDM/TDM PON. NRZ rectangular emerged as the most appropriate modulation format for triple play transmission in the proposed hybrid PON. PMID:27382633

Intraindividual Analysis of Signal Intensity Changes in the Dentate Nucleus After Consecutive Serial Applications of Linear and Macrocyclic Gadolinium-Based Contrast Agents.

PubMed

Radbruch, Alexander; Weberling, Lukas D; Kieslich, Pascal J; Hepp, Johanna; Kickingereder, Philipp; Wick, Wolfgang; Schlemmer, Heinz-Peter; Bendszus, Martin

2016-11-01

Recent studies reported an increase in the dentate nucleus (DN)-to-pons signal intensity (SI) ratio (DN-pons SI ratio) on unenhanced T1-weighted images in patients who received consecutive serial injections of linear gadolinium-based contrast agents (GBCAs). In contrast, most studies found no increase in the DN-pons SI ratio when patients were treated with consecutive serial injections of macrocyclic GBCAs. However, the potential difference between macrocyclic and linear GBCAs has never been assessed in individuals who received subsequent applications of both contrast agents. In this retrospective study, we assessed the evolution of the DN-pons SI ratio change in patients that were treated with a comparable number of serial consecutive injections of the linear GBCA gadopentetate dimeglumine and subsequent serial injections of the macrocyclic GBCAs gadobutrol and gadoterate meglumine. Data of 36 patients was analyzed. All patients underwent at least 5 consecutive administrations of the linear GBCA gadopentetate dimeglumine followed by an equal number of consecutive administrations of the macrocyclic GBCA gadobutrol. In 12 of the 36 patients, 5 or more final consecutive injections of the macrocyclic GBCA gadoterate meglumine were analyzed additionally. The difference of DN-pons SI ratios on unenhanced T1-weighted images was calculated by subtracting the ratio at the first examination from the ratio at the last examination in each of the 3 periods. The mean DN-pons SI ratio difference in the gadopentetate dimeglumine period was significantly greater than 0 (mean ± SD, 0.0448 ± 0.0345; P < 0.001), whereas the mean DN-pons SI ratio difference in the subsequent gadobutrol and gadoterate meglumine period was significantly smaller than 0 (gadobutrol: -0.0178 ± 0.0459, P = 0.026; gadoterate meglumine: -0.0250 ± 0.0284, P = 0.011). In this observational study, the application of the linear GBCA gadopentetate dimeglumine was associated with a DN-pons SI ratio increase, whereas subsequent applications of the macrocyclic GBCAs gadobutrol or gadoterate meglumine in the same patients were not. Rather, the current data tentatively suggest a decrease in preexisting hyperintensities over time when linear GBCAs are changed to macrocyclic GBCAs, potentially indicating a washout effect or precipitation of gadolinium. Future patient studies need to include control groups to replicate the present results, and additional animal studies should be conducted to clarify the underlying mechanism of the proposed SI decrease.

GLYOXALASE I A111E, PARAOXONASE 1 Q192R AND L55M POLYMORPHISMS IN ITALIAN PATIENTS WITH SPORADIC CEREBRAL CAVERNOUS MALFORMATIONS: A PILOT STUDY.

PubMed

Rinaldi, C; Bramanti, P; Famà, A; Scimone, C; Donato, L; Antognelli, C; Alafaci, C; Tomasello, F; D'Angelo, R; Sidoti, A

2015-01-01

It is already known that the conditions of increased oxidative stress are associated to a greater susceptibility to vascular malformations including cerebral cavernous malformations (CCMs). These are vascular lesions of the CNS characterized by abnormally enlarged capillary cavities that can occur sporadically or as a familial autosomal dominant condition with incomplete penetrance and variable clinical expression attributable to mutations in three different genes: CCM1(Krit1), CCM2 (MGC4607) and CCM3 (PDCD10). Polymorphisms in the genes encoding for enzymes involved in the antioxidant systems such as glyoxalase I (GLO I) and paraoxonase I (PON I) could influence individual susceptibility to the vascular malformations. A single nucleotide polymorphism was identified in the exon 4 of GLO 1 gene that causes an amino acid substitution of Ala for Glu (Ala111Glu). Two common polymorphisms have been described in the coding region of PON1, which lead to glutamine → arginine substitution at 192 (Q192R) and a leucine → methionine substitution at 55 (L55M). The polymorphisms were characterized in 59 patients without mutations in the CCM genes versus 213 healthy controls by PCR/RFLP methods using DNA from lymphocytes. We found that the frequency of patients carrying the GLO1 A/E genotype among the case group (56%) was four-fold higher than among the controls (14.1%). In the cohort of CCM patients, an increase in the frequency of PON192 Q/R genotype was observed (39% in the CCM group versus 3.7% in the healthy controls). Similarly, an increase was observed in the proportion of individuals with the genotype R/R in the disease group (5%) in respect to the normal healthy cohort (0.5%). Finally, the frequency of the PON55 heterozygotes L/M genotype was 29% in patients with CCMs and 4% in the healthy controls. The same trend was observed in PON55 homozygous M/M genotype frequency (CCMs 20% vs controls 10%). The present study aimed to investigate the possible association of GLO1 A111E, PON1 Q192R and L55M polymorphisms with the risk of CCMs. We found that individuals with the GLO1 A /E genotype, PON192/QR-RR genotypes and PON55/LM-MM genotypes had a significantly higher risk of CCMs compared with the other genotypes. However, because CCM is a heterogeneous disease, other additional factors might be involved in the initiation and progression of CCM disease.

Serum paraoxonase type-1 activity in pigs: assay validation and evolution after an induced experimental inflammation.

PubMed

Escribano, Damián; Tvarijonaviciute, Asta; Tecles, Fernando; Cerón, José J

2015-02-15

Paraoxonase 1 (PON1) is a serum enzyme synthesised and secreted primarily by the liver. It possesses anti-inflammatory properties limiting the production of pro-inflammatory mediators. The objectives of this study were to validate three spectrophotometric assays for the quantification of PON1 activity in pig serum, and to determine if PON1 activity in porcine behaves as a negative acute phase protein (APP), decreasing in inflammatory conditions. An analytical validation using three different substrates - 5-thiobutil butyrolactone (TBBL), phenylacetate (PA) and 4-(p)-nitrophenyl acetate (pNA) - was performed. In addition, inflammation was experimentally induced in five pigs by subcutaneous injection of turpentine oil, while five control pigs were left untreated. The treated pigs showed significant increases in CRP and decreases in albumin, indicating an inflammatory condition. The three substrates used would be suitable for PON1 activity measurements in serum samples, since they offer adequate precision (coefficients of variation<10%), sensitivity (0.01, 0.15, 0.02 U/mL for TBBL, pNA and PA respectively) and accuracy (r=0.99). In addition, PON1 behaves as a negative APP in pigs since a significant decrease (P<0.05) in its activity after 72 h of the induction of the inflammation was observed with all substrates. Copyright © 2015 Elsevier B.V. All rights reserved.

Serum concentrations of trace elements and their relationships with paraoxonase-1 in morbidly obese women.

PubMed

Luciano-Mateo, Fedra; Cabré, Noemí; Nadal, Martí; García-Heredia, Anabel; Baiges-Gaya, Gerard; Hernández-Aguilera, Anna; Camps, Jordi; Joven, Jorge; Domingo, José Luis

2018-07-01

The metabolic alterations associated with obesity include mineral dysregulation. Essential trace elements are nutrients with a relevant function in a large number of cellular processes and multiple roles in the correct functioning of metabolic enzymes. Paraoxonase-1 (PON1) is an antioxidant and anti-inflammatory enzyme that is compromised in obesity. In the present study, the potential alterations in trace elements in morbidly obese women were assessed in relation to serum PON1 activity and concentration, as well as to other obesity-related comorbidities such as diabetes mellitus and fatty liver. We recruited 41 morbidly obese women and 51 control individuals. The serum concentrations of 30 elements, PON1 paraoxonase and lactonase activities, and PON1 concentration were measured. We observed significant alterations in the levels of As, Ba, Cu, Ca, Fe, Mg, Na, Se, Sr, and Zn in obese women; some of them (As, Ca, Cr, Cu, Mg, and Se) being significantly correlated with serum PON1 values. The most relevant changes were observed in the concentrations of As, Sr and Mg, the last of which was also significantly associated with diabetes mellitus. The current results raise the possibility that increased ingestion and/or storage of a number of trace elements may be factors predisposing to obesity-related comorbidities and metabolic alterations. Copyright © 2018 Elsevier GmbH. All rights reserved.

Common variants APOC3, APOA5, APOE and PON1 are associated with variation in plasma lipoprotein traits in Greenlanders.

PubMed

Lahiry, Piya; Ban, Matthew R; Pollex, Rebecca L; Feldman, Ross D; Sawyez, Cynthia G; Huff, Murray W; Young, T Kue; Bjerregaard, Peter; Hegele, Robert A

2007-12-01

We undertook studies of the association between common genomic variations in APOC3, APOA5, APOE and PON1 genes and variation in biochemical phenotypes in a sample of Greenlanders. Genetic association study of quantitative lipoprotein traits. In a sample of 1,310 adult Greenlanders, fasting plasma lipid, lipoprotein and apolipoprotein (apo) concentrations were assessed for association with known functional genomic variants of APOC3, APOA5, APOE and PON1. For significantly associated polymorphisms, between-genotype differences were examined in closer detail. We found that (1) the APOE restriction isotype was associated with variation in plasma total and LDL cholesterol and apo B (all p < .0001); (2) the APOC3 promoter genotype was associated with variation in plasma triglycerides, HDL cholesterol and apo A-I (all p < .002); (3) the APOA5 codon 19 genotype was associated with variation in plasma triglycerides (p = .027); and (4) the PON1 codon 192 genotype was associated with variation in total and LDL cholesterol and apo B (all p < .05). Taken together, our results suggest that common genetic variations in APOC3, APOA5, APOE and PON1 are associated with significant variation in intermediate traits in plasma lipoprotein metabolism in Greenlanders; the associations are similar to those observed for these variants in other populations.

Serum Protein KNG1, APOC3, and PON1 as Potential Biomarkers for Yin-Deficiency-Heat Syndrome.

PubMed

Liu, Changming; Mao, Liangen; Ping, Zepeng; Jiang, Tingting; Wang, Chong; Chen, Zhongliang; Li, Zhongjie; Li, Jicheng

2016-01-01

Yin-deficiency-heat (YDH) syndrome is a concept in Traditional Chinese Medicine (TCM) for describing subhealth status. However, there are few efficient diagnostic methods available for confirming YDH syndrome. To explore the novel method for diagnosing YDH syndrome, we applied iTRAQ to observe the serum protein profiles in YDH syndrome rats and confirmed protein levels by ELISA. A total of 92 differentially expressed proteins (63 upregulated proteins and 29 downregulated proteins), which were mainly involved in complement and coagulation cascades and glucose metabolism pathway, were identified by the proteomic experiments. Kininogen 1 (KNG1) was significantly increased ( p < 0.0001), while apolipoprotein C-III (APOC3, p < 0.005) and paraoxonase 1 (PON1, p < 0.001) were significantly decreased in the serum of YDH syndrome rats. The combination of KNG1, APOC3, and PON1 constituted a diagnostic model with 100.0% sensitivity and 85.0% specificity. The results indicated that KNG1, APOC3, and PON1 may act as potential biomarkers for diagnosing YDH syndrome. KNG1 may regulate cytokines and chemokines release in YDH syndrome, and the low levels of PON1 and APOC3 may increase oxidative stress and lipolysis in YDH syndrome, respectively. Our work provides a novel method for YDH syndrome diagnosis and also provides valuable experimental basis to understand the molecular mechanism of YDH syndrome.

Paraoxonase polymorphisms PON1 192 and 55 and longevity in Italian centenarians and Irish nonagenarians. A pooled analysis.

PubMed

Rea, Irene M; McKeown, Pascal P; McMaster, Dorothy; Young, Ian S; Patterson, Chris; Savage, Maurice J; Belton, Christine; Marchegiani, Francesca; Olivieri, Fabiola; Bonafe, Massimiliano; Franceschi, Claudio

2004-04-01

PON1, an arylesterase, associated with high density lipoprotein (HDL), protects low density lipoprotein (LDL) against oxidative modification. Common polymorphisms PON1 55 (L/M) and 192 (Q/R) in the PON1 gene associate with atherosclerosis and heart disease. Because long-lived people seem protected from premature vascular death, we conducted a pooled statistical analysis to assess any association between these polymorphisms and longevity in a large combined group of Italian centenarians and octo/nonagenarians from Northern Ireland (NI). Separated DNA was available from 1479 subjects from Italy and Northern Ireland (NI). In Italy 308 centenarians (males 67, females 241, mean age 100.8, SD2.1 years) and 579 young controls (males 347, females 232, mean age 40.7, SD 12.7 years) were included in the study. In NI, 296 octo/nonagenarians (males 92, females 204, mean age 89.8, SD 5.7 years) and 296 young sex-matched subjects (mean age 13.0, SD 1.4 years) had available DNA. PON1 55 (L/M) and 192 (Q/R) polymorphisms were studied using a PCR-RFLP approach. There was a significant difference in PON1 192 genotypes in Italian centenarians compared to younger controls (X(2)= 6.8, df = 2 p= 0.03) and a similar but non significant trend between octo/nonagenarian and young subjects in NI (X(2) = 4.0, df=2, p=0.14). Using logistic regression analysis on the combined Italian and Irish datasets, there was a small survival advantage for centenarian and octo/nonagenarian subjects who were heterozygous for PON1 192 R allele, (OR 1.3, CI 1-1.6; p=0.04 with a stepwise increase for RR homozygous subjects (OR 1.7, CI 1.1-2.6; p = 0.02) compared to QQ subjects. Comparing R and Q alleles there was a survival advantage for octo/nonagenarian/centenarian subjects who carried the R allele (OR 1.3, CI 1.1-1.5; p = 0.007) but there was no sex-specific effect p =0.77) LL, LM and MM genotypes of PON 55 polymorphisms showed similar frequencies in Italy (39.9, 47.0, 13.1%) and Ireland (39.5, 48.6, 11.9%) with no age or sex-related differences. The PON1 192R/Q and PON55L/M loci were in strong linkage disequilibrium with a Lewontin's D' coefficient -0.928 (elderly) and -0.965 (young). There was a significant difference in haplotype frequency of these linked loci in older compared to younger subjects (Likelihood Ratio X(2) = 9.60, df = 3, p= 0.02). These data suggest a modest association between the 192R allele and longevity in two very elderly populations in two European countries. Being homozygous for 192 RR further enhances survival advantage but this effect was not found to be sex specific. This finding is of interest because the 192R allele has previously been associated with increased risk of coronary heart disease. On the other hand, the 192R allele shows higher enzymatic activity, using paraoxon as substrate, and we postulate that its role in the metabolism of potentially toxic chemicals or other metabolic pathways may be important in survival to very old age.

Differentiated protection method in passive optical networks based on OPEX

NASA Astrophysics Data System (ADS)

Zhang, Zhicheng; Guo, Wei; Jin, Yaohui; Sun, Weiqiang; Hu, Weisheng

2011-12-01

Reliable service delivery becomes more significant due to increased dependency on electronic services all over society and the growing importance of reliable service delivery. As the capability of PON increasing, both residential and business customers may be included in a PON. Meanwhile, OPEX have been proven to be a very important factor of the total cost for a telecommunication operator. Thus, in this paper, we present the partial protection PON architecture and compare the operational expenditures (OPEX) of fully duplicated protection and partly duplicated protection for ONUs with different distributed fiber length, reliability requirement and penalty cost per hour. At last, we propose a differentiated protection method to minimize OPEX.

An AWG-based 10 Gbit/s colorless WDM-PON system using a chirp-managed directly modulated laser

NASA Astrophysics Data System (ADS)

Latif, Abdul; Yu, Chong-xiu; Xin, Xiang-jun; Husain, Aftab; Hussain, Ashiq; Munir, Abid; Khan, Yousaf

2012-09-01

We propose an arrayed waveguide grating (AWG)-based 10 Gbit/s per channel full duplex wavelength division multiplexing passive optical network (WDM-PON). A chirp managed directly modulated laser with return-to-zero (RZ) differential phase shift keying (DPSK) modulation technique is utilized for downlink (DL) direction, and then the downlink signal is re-modulated for the uplink (UL) direction using intensity modulation technique with the data rate of 10 Gbit/s per channel. A successful WDM-PON transmission operation with the data rate of 10 Gbit/s per channel over a distance of 25 km without any optical amplification or dispersion compensation is demonstrated with low power penalty.

Real-time monitoring implementation in a remote-pumped WDM PON

NASA Astrophysics Data System (ADS)

Liaw, S.-K.; Hong, K.-L.; Shei, Y.-S.

2008-08-01

We report on an improved configuration to monitor a passive optical network with high quality in service. This proposed system comprises fiber-Bragg gratings, a 1 × 4 optical switch, and an optical time-domain reflectometry to diagnose the broken point in real time. It could simultaneously detect multioptical network units in a WDM PON. The remote-pump integrated residual pumping reused function is implemented. Broken points in different optical paths can be detected simultaneously even when the distances to the central office are identical. The bit-error rate testing is verified with a small power penalty, making it an ideal solution for the real-time monitoring in a WDM PON.

The 40 Gbps cascaded bit-interleaving PON

NASA Astrophysics Data System (ADS)

Vyncke, A.; Torfs, G.; Van Praet, C.; Verbeke, M.; Duque, A.; Suvakovic, D.; Chow, H. K.; Yin, X.

2015-12-01

In this paper, a 40 Gbps cascaded bit-interleaving passive optical network (CBI-PON) is proposed to achieve power reduction in the network. The massive number of devices in the access network makes that power consumption reduction in this part of the network has a major impact on the total network power consumption. Starting from the proven BiPON technology, an extension to this concept is proposed to introduce multiple levels of bit-interleaving. The paper discusses the CBI protocol in detail, as well as an ASIC implementation of the required custom CBI Repeater and End-ONT. From the measurements of this first 40 Gbps ASIC prototype, power consumption reduction estimates are presented.

Wired/wireless access integrated RoF-PON with scalable generation of multi-frequency MMWs enabled by polarization multiplexed FWM in SOA.

PubMed

Xiang, Yu; Chen, Chen; Zhang, Chongfu; Qiu, Kun

2013-01-14

In this paper, we propose and demonstrate a novel integrated radio-over-fiber passive optical network (RoF-PON) system for both wired and wireless access. By utilizing the polarization multiplexed four-wave mixing (FWM) effect in a semiconductor optical amplifier (SOA), scalable generation of multi-frequency millimeter-waves (MMWs) can be provided so as to assist the configuration of multi-frequency wireless access for the wire/wireless access integrated ROF-PON system. In order to obtain a better performance, the polarization multiplexed FWM effect is investigated in detail. Simulation results successfully verify the feasibility of our proposed scheme.

Fault discovery protocol for passive optical networks

NASA Astrophysics Data System (ADS)

Hajduczenia, Marek; Fonseca, Daniel; da Silva, Henrique J. A.; Monteiro, Paulo P.

2007-06-01

All existing flavors of passive optical networks (PONs) provide an attractive alternative to legacy copper-based access lines deployed between a central office (CO) of the service provider (SP) and a customer site. One of the most challenging tasks for PON network planners is the reduction of the overall cost of employing protection schemes for the optical fiber plant while maintaining a reasonable level of survivability and reducing the downtime, thus ensuring acceptable levels of quality of service (QoS) for end subscribers. The recently growing volume of Ethernet PONs deployment [Kramer, IEEE 802.3, CFI (2006)], connected with low-cost electronic and optical components used in the optical network unit (ONU) modules, results in the situation where remote detection of faulty/active subscriber modules becomes indispensable for proper operation of an EPON system. The problem of the remote detection of faulty ONUs in the system is addressed where the upstream channel is flooded with the cw transmission from one or more damaged ONUs and standard communication is severed, providing a solution that is applicable in any type of PON network, regardless of the operating protocol, physical structure, and data rate.

Power budget enhancement in NG-EPON system employing novel twisted-PAM4

NASA Astrophysics Data System (ADS)

Li, Longsheng; Bi, Meihua; Fu, Yan; Miao, Xin; Zhu, Qingming; Hu, Weisheng

2018-03-01

In this paper, we firstly design a novel modulation format named Twisted-PAM4 (T-PAM4) for the high-speed NG-EPON and the PON-based digital fronthaul system. Compared to other high-order modulation formats like 4-ary pulse amplitude modulation (PAM4), T-PAM4 provides two independent sampling values in each symbol period and enables two-dimensional symbol decision, which significantly improves the receiver sensitivity and hence enlarges the system power budget. Based on this advantage, six types of T-PAM4 are experimentally demonstrated in 28-Gb/s/ λ NG-PON and 32-Gb/s/ λ PON-based digital fronthaul system. The experimental results show that, compared to the ordinary PAM4, the T-PAM4 can bring 5-dB and 4-dB extra power budget in NG-EPON and PON-based fronthaul system respectively. In addition, by experiment, it is also depicted that the T-PAM4 is remarkably robust to system nonlinearity, which would ease the linearity requirement on system components and hence reduce system cost.

Frequency Response of Synthetic Vocal Fold Models with Linear and Nonlinear Material Properties

PubMed Central

Shaw, Stephanie M.; Thomson, Scott L.; Dromey, Christopher; Smith, Simeon

2014-01-01

Purpose The purpose of this study was to create synthetic vocal fold models with nonlinear stress-strain properties and to investigate the effect of linear versus nonlinear material properties on fundamental frequency during anterior-posterior stretching. Method Three materially linear and three materially nonlinear models were created and stretched up to 10 mm in 1 mm increments. Phonation onset pressure (Pon) and fundamental frequency (F0) at Pon were recorded for each length. Measurements were repeated as the models were relaxed in 1 mm increments back to their resting lengths, and tensile tests were conducted to determine the stress-strain responses of linear versus nonlinear models. Results Nonlinear models demonstrated a more substantial frequency response than did linear models and a more predictable pattern of F0 increase with respect to increasing length (although range was inconsistent across models). Pon generally increased with increasing vocal fold length for nonlinear models, whereas for linear models, Pon decreased with increasing length. Conclusions Nonlinear synthetic models appear to more accurately represent the human vocal folds than linear models, especially with respect to F0 response. PMID:22271874

Universal filtered multi-carrier system for asynchronous uplink transmission in optical access network

NASA Astrophysics Data System (ADS)

Kang, Soo-Min; Kim, Chang-Hun; Han, Sang-Kook

2016-02-01

In passive optical network (PON), orthogonal frequency division multiplexing (OFDM) has been studied actively due to its advantages such as high spectra efficiency (SE), dynamic resource allocation in time or frequency domain, and dispersion robustness. However, orthogonal frequency division multiple access (OFDMA)-PON requires tight synchronization among multiple access signals. If not, frequency orthogonality could not be maintained. Also its sidelobe causes inter-channel interference (ICI) to adjacent channel. To prevent ICI caused by high sidelobes, guard band (GB) is usually used which degrades SE. Thus, OFDMA-PON is not suitable for asynchronous uplink transmission in optical access network. In this paper, we propose intensity modulation/direct detection (IM/DD) based universal filtered multi-carrier (UFMC) PON for asynchronous multiple access. The UFMC uses subband filtering to subsets of subcarriers. Since it reduces sidelobe of each subband by applying subband filtering, it could achieve better performance compared to OFDM. For the experimental demonstration, different sample delay was applied to subbands to implement asynchronous transmission condition. As a result, time synchronization robustness of UFMC was verified in asynchronous multiple access system.

Frequency response of synthetic vocal fold models with linear and nonlinear material properties.

PubMed

Shaw, Stephanie M; Thomson, Scott L; Dromey, Christopher; Smith, Simeon

2012-10-01

The purpose of this study was to create synthetic vocal fold models with nonlinear stress-strain properties and to investigate the effect of linear versus nonlinear material properties on fundamental frequency (F0) during anterior-posterior stretching. Three materially linear and 3 materially nonlinear models were created and stretched up to 10 mm in 1-mm increments. Phonation onset pressure (Pon) and F0 at Pon were recorded for each length. Measurements were repeated as the models were relaxed in 1-mm increments back to their resting lengths, and tensile tests were conducted to determine the stress-strain responses of linear versus nonlinear models. Nonlinear models demonstrated a more substantial frequency response than did linear models and a more predictable pattern of F0 increase with respect to increasing length (although range was inconsistent across models). Pon generally increased with increasing vocal fold length for nonlinear models, whereas for linear models, Pon decreased with increasing length. Nonlinear synthetic models appear to more accurately represent the human vocal folds than do linear models, especially with respect to F0 response.

Observations on particulate organic nitrates and unidentified components of NO y

NASA Astrophysics Data System (ADS)

Nielsen, Torben; Egeløv, Axel H.; Granby, Kit; Skov, Henrik

A method to determine the total content of particulate organic nitrates (PON) has been developed and ambient air measurements of PON, NO, N02, HNO3, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), gas NOY and particulate inorganic nitrate have been performed in the spring and early summer at an agricultural site in Denmark and compared with measurements of ozone, H 2O 2, SO 2, formic acid, acetic acid and methane sulphonic acid. The gas NO y detector determines the sum NO + NO 2 + HNO 2 + HNO 3 + PAN + PPN + gas phase organic nitrates + 2 × N 2O 5 + NO 3. The content of residual gas NO y ( = gas NO y - NO - NO 2 - HNO 3 - PAN - PPN) was determined and a group of unidentified NO y compounds was found. The phenomenon was observed at a site with relatively high NO x/NO y ratios compared to previous observations in U.S.A. and Canada. The residual gas NO y made up 7 ± 6% of total NOY (total NO y = gas NO y + particulate inorganic nitrate). Residual gas NO y was much higher than the particulate fraction of organic nitrates (PON). PON was only 0.25 ± 0.11% of total NO y. Both residual gas NO y and particulate organic nitrates episodes occurred with elevated concentrations of photochemical oxidants in connection with high-pressure systems suggesting atmospheric processes being the major source. Clean marine air can be discarded as a source for PON and residual gas NO y.

Pirenzepine binding to membrane-bound, solubilized and purified muscarinic receptor subtypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumgold, J.

1986-05-01

Muscarinic receptors were purified to near-homogeneity from bovine cortex, an area rich in the putative M1 subtype, and from bovine pons/medulla, an area rich in the putative M2 subtype. In both cases, the receptors were solubilized in digitonin and purified over an affinity column. Both the cortical and pons/medulla preparations yielded receptor proteins of 70,000 daltons. Pirenzepine binding was deduced from its competition with /sup 3/H-N-methyl scopolamine. The binding of pirenzepine to membrane-bound receptors from cortex was best described by a two site model, with approximately half the sites having a Ki of 6.4 x 10/sup -9/ M and themore » remaining sites having a Ki of 3.5 x 10/sup -7/ M. Membrane-bound receptors from pons/medulla bound pirenzepine according to a one-site model with a Ki of 1.1 x 10/sup -7/ M. After solubilization the two-site binding of cortical receptors became a one-site binding, Ki = 1.1 x 10/sup -7/M. This value was still five-fold lower than that of soluble receptors from pons/medulla. After purification however the affinity of pirenzepine for the pons/medulla receptor increased so that the two putative subtypes bound pirenzepine with approximately the same affinity. These findings suggest that the different pirenzepine binding characteristics used to define muscarinic receptor subtypes are not inherent in the receptor protein itself but may be due to coupling factors associated with the receptor.« less

Impact of the 24-h ultramarathon race on homocysteine, oxidized low-density lipoprotein, and paraoxonase 1 levels in professional runners

PubMed Central

Benedetti, Serena; Catalani, Simona; Peda, Federica; Luchetti, Francesca; Citarella, Roberto; Battistelli, Serafina

2018-01-01

The impact of the 24-h ultramarathon race on homocysteine (Hcy) and oxidized low-density lipoprotein (oxLDL) levels, two well-recognized cardiovascular risk factors, has not been deeply investigated. Similarly, no information exists on paraoxonase 1 (PON1), an antioxidant enzyme associated with high-density lipoproteins, which may detoxify oxLDL and Hcy-thiolactone, hence preventing their proatherogenic action. Taking this into account, a competitive 24-h ultramarathon race was organized in Reggio-Emilia (Italy) recruiting professional runners (n = 14) from the Italian Ultramarathon and Trail Association. Blood samples were collected from each participant before, during (14 h), and immediately after (24 h) the competition, thus to monitor the serum changes in Hcy, oxLDL, and PON1 levels, as well as other oxidative stress-related parameters, namely reactive oxygen metabolites (ROM) and total antioxidant capacity (PAT). As a result, a significant PON1 increase was recorded after 14 h of racing that persisted until the end of the performance. The same trend was observed for PAT values, which positively correlated to PON1 levels (R = 0.643, P<0.001). Hcy, oxLDL, and ROM remained almost unchanged throughout the competition. In conclusion, the present study suggested a protective role of PON1 in sustaining the antioxidant defense system and contrasting lipoprotein oxidative modifications over the 24-h race, and did not specifically evidence either Hcy or oxLDL accumulation in such challenging sporting events. PMID:29394290

Impact of the 24-h ultramarathon race on homocysteine, oxidized low-density lipoprotein, and paraoxonase 1 levels in professional runners.

PubMed

Benedetti, Serena; Catalani, Simona; Peda, Federica; Luchetti, Francesca; Citarella, Roberto; Battistelli, Serafina

2018-01-01

The impact of the 24-h ultramarathon race on homocysteine (Hcy) and oxidized low-density lipoprotein (oxLDL) levels, two well-recognized cardiovascular risk factors, has not been deeply investigated. Similarly, no information exists on paraoxonase 1 (PON1), an antioxidant enzyme associated with high-density lipoproteins, which may detoxify oxLDL and Hcy-thiolactone, hence preventing their proatherogenic action. Taking this into account, a competitive 24-h ultramarathon race was organized in Reggio-Emilia (Italy) recruiting professional runners (n = 14) from the Italian Ultramarathon and Trail Association. Blood samples were collected from each participant before, during (14 h), and immediately after (24 h) the competition, thus to monitor the serum changes in Hcy, oxLDL, and PON1 levels, as well as other oxidative stress-related parameters, namely reactive oxygen metabolites (ROM) and total antioxidant capacity (PAT). As a result, a significant PON1 increase was recorded after 14 h of racing that persisted until the end of the performance. The same trend was observed for PAT values, which positively correlated to PON1 levels (R = 0.643, P<0.001). Hcy, oxLDL, and ROM remained almost unchanged throughout the competition. In conclusion, the present study suggested a protective role of PON1 in sustaining the antioxidant defense system and contrasting lipoprotein oxidative modifications over the 24-h race, and did not specifically evidence either Hcy or oxLDL accumulation in such challenging sporting events.

Açai (Euterpe oleracea Mart.) Upregulates Paraoxonase 1 Gene Expression and Activity with Concomitant Reduction of Hepatic Steatosis in High-Fat Diet-Fed Rats

PubMed Central

Lage, Nara Nunes; Lopes, Juliana Márcia Macedo; de Lima, Wanderson Geraldo

2016-01-01

Açai (Euterpe oleracea Mart.), a fruit from the Amazon region, has emerged as a promising source of polyphenols. Açai consumption has been increasing owing to ascribed health benefits and antioxidant properties; however, its effects on hepatic injury are limited. In this study, we evaluated the antioxidant effect of filtered açai pulp on the expression of paraoxonase (PON) isoforms and PON1 activity in rats with nonalcoholic fatty liver disease (NAFLD). The rats were fed a standard AIN-93M (control) diet or a high-fat (HF) diet containing 25% soy oil and 1% cholesterol with or without açai pulp (2 g/day) for 6 weeks. Our results show that açai pulp prevented low-density lipoprotein (LDL) oxidation, increased serum and hepatic PON1 activity, and upregulated the expression of PON1 and ApoA-I in the liver. In HF diet-fed rats, treatment with açai pulp attenuated liver damage, reducing fat infiltration and triglyceride (TG) content. In rats receiving açai, increased serum PON1 activity was correlated with a reduction in hepatic steatosis and hepatic injury. These findings suggest the use of açai as a potential therapy for liver injuries, supporting the idea that dietary antioxidants are a promising approach to enhance the defensive systems against oxidative stress. PMID:27642496

Açai (Euterpe oleracea Mart.) Upregulates Paraoxonase 1 Gene Expression and Activity with Concomitant Reduction of Hepatic Steatosis in High-Fat Diet-Fed Rats.

PubMed

Pereira, Renata Rebeca; de Abreu, Isabel Cristina Mallosto Emerich; Guerra, Joyce Ferreira da Costa; Lage, Nara Nunes; Lopes, Juliana Márcia Macedo; Silva, Maísa; de Lima, Wanderson Geraldo; Silva, Marcelo Eustáquio; Pedrosa, Maria Lucia

2016-01-01

Açai (Euterpe oleracea Mart.), a fruit from the Amazon region, has emerged as a promising source of polyphenols. Açai consumption has been increasing owing to ascribed health benefits and antioxidant properties; however, its effects on hepatic injury are limited. In this study, we evaluated the antioxidant effect of filtered açai pulp on the expression of paraoxonase (PON) isoforms and PON1 activity in rats with nonalcoholic fatty liver disease (NAFLD). The rats were fed a standard AIN-93M (control) diet or a high-fat (HF) diet containing 25% soy oil and 1% cholesterol with or without açai pulp (2 g/day) for 6 weeks. Our results show that açai pulp prevented low-density lipoprotein (LDL) oxidation, increased serum and hepatic PON1 activity, and upregulated the expression of PON1 and ApoA-I in the liver. In HF diet-fed rats, treatment with açai pulp attenuated liver damage, reducing fat infiltration and triglyceride (TG) content. In rats receiving açai, increased serum PON1 activity was correlated with a reduction in hepatic steatosis and hepatic injury. These findings suggest the use of açai as a potential therapy for liver injuries, supporting the idea that dietary antioxidants are a promising approach to enhance the defensive systems against oxidative stress.

The effects of resveratrol on hepatic oxidative stress in metabolic syndrome model induced by high fructose diet.

PubMed

Yilmaz Demirtas, C; Bircan, F S; Pasaoglu, O T; Turkozkan, N

2018-01-01

The purpose of this study was to evaluate probable protective effects of resveratrol treatment on hepatic oxidative events in a rat model of metabolic syndrome (MetS). Thirty-two male adult rats were randomly divided into 4 groups: control, fructose, resveratrol, and fructose plus resveratrol. To induce MetS, fructose solution (20 % in drinking water) was used. Resveratrol (10 mg/kg/day) was given by oral gavage. All treatments were given for 8 weeks. Serum lipid profile, glucose and insulin levels, liver total oxidant status (TOS) levels and paraoxonase (PON), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities were analyzed. Fructose-fed rats displayed statistically significant increases in TOS levels, and decreases in PON activity compared to the control group. Resveratrol treatment moderately prevented the decrease in liver PON activity caused by fructose. On the other hand, resveratrol, alone or in combination with fructose, did not change the TOS levels when compared to the fructose group. The SOD and CAT activities in all groups did not change. In this experimental design, high-fructose consumption led to elevated TOS levels and low PON activities. The resveratrol therapy shown beneficial effects on PON activity. However, it was found to behave like a prooxidant when administered together with fructose and alone in some parameters. Our results can inspire the development of new clinical therapy in patients with MetS (Tab. 2, Ref. 34).

Correlation of Paraoxonase Status with Disease Activity Score and Systemic Inflammation in Rheumatoid Arthritic Patients.

PubMed

Bindal, Usha Dudeja; Saxena, Rahul; Siddiqui, Merajul Haque; Sharma, Dilutpal

2016-03-01

Despite, various preventive efforts on conventional cardiovascular disease (CVD) risk factors, the incidence of CVD in rheumatoid arthritis (RA) patients increases continuously. To solve this conundrum one needs more investigations. The present study was conducted to evaluate the plasma paraoxonase (PON) activity along with the markers of systemic inflammation, oxidative stress and disease activity score-28 (DAS28) in RA patients and clarify their role in determining the probability of RA patients to develop future CVD risk. Plasma PON, total antioxidant activity (TAA), C-reactive protein (CRP), synovial interleukin-6 (IL-6) and erythrocyte malondialdehyde (MDA) levels were estimated in 40 RA patients aged 40-55 years aged and 40 age-matched healthy controls. The data obtained were compared statistically by using Student's t-test and Pearson correlation test. Besides dyslipidaemia, marked reduction in plasma PON and TAA (p< 0.05) were observed in RA patients as compared with that of healthy controls. Erythrocyte MDA, plasma CRP and synovial IL-6 levels were increased significantly (p<0.05) in RA patients. PON was negatively correlated with MDA (r = - 0.672; p < 0.001), CRP (r = -0.458; p<0.05), IL-6 (r = -0.426; p<0.05) and DAS28 (r = -0.598; p < 0.001), and positively correlated with HDL cholesterol (r = 0.648; p<0.001) and TAA (r = 0.608; p< 0.001) levels in RA patients. Alteration in PON activity might contribute to the progression of future CVD risk in RA patients, which may result from interplay of several confounding factors, such as inflammation, oxidative stress and dyslipidaemia. Furthermore, plasma PON activity, CRP and TAA levels could be considered as non-traditional factors to predict CVD risk. Thus, it is suggested that future drugs could be developed to target the non-traditional risk factors in RA patients.

Application of advanced data collection and quality assurance methods in open prospective study - a case study of PONS project.

PubMed

Wawrzyniak, Zbigniew M; Paczesny, Daniel; Mańczuk, Marta; Zatoński, Witold A

2011-01-01

Large-scale epidemiologic studies can assess health indicators differentiating social groups and important health outcomes of the incidence and mortality of cancer, cardiovascular disease, and others, to establish a solid knowledgebase for the prevention management of premature morbidity and mortality causes. This study presents new advanced methods of data collection and data management systems with current data quality control and security to ensure high quality data assessment of health indicators in the large epidemiologic PONS study (The Polish-Norwegian Study). The material for experiment is the data management design of the large-scale population study in Poland (PONS) and the managed processes are applied into establishing a high quality and solid knowledge. The functional requirements of the PONS study data collection, supported by the advanced IT web-based methods, resulted in medical data of a high quality, data security, with quality data assessment, control process and evolution monitoring are fulfilled and shared by the IT system. Data from disparate and deployed sources of information are integrated into databases via software interfaces, and archived by a multi task secure server. The practical and implemented solution of modern advanced database technologies and remote software/hardware structure successfully supports the research of the big PONS study project. Development and implementation of follow-up control of the consistency and quality of data analysis and the processes of the PONS sub-databases have excellent measurement properties of data consistency of more than 99%. The project itself, by tailored hardware/software application, shows the positive impact of Quality Assurance (QA) on the quality of outcomes analysis results, effective data management within a shorter time. This efficiency ensures the quality of the epidemiological data and indicators of health by the elimination of common errors of research questionnaires and medical measurements.

Aromatherapy as treatment for postoperative nausea: a randomized trial.

PubMed

Hunt, Ronald; Dienemann, Jacqueline; Norton, H James; Hartley, Wendy; Hudgens, Amanda; Stern, Thomas; Divine, George

2013-09-01

Postoperative nausea (PON) is a common complication of anesthesia and surgery. Antiemetic medication for higher-risk patients may reduce but does not reliably prevent PON. We examined aromatherapy as a treatment for patients experiencing PON after ambulatory surgery. Our primary hypothesis was that in comparison with inhaling a placebo, PON will be reduced significantly by aromatherapy with (1) essential oil of ginger, (2) a blend of essential oils of ginger, spearmint, peppermint, and cardamom, or (3) isopropyl alcohol. Our secondary hypothesis was that the effectiveness of aromatherapy will depend upon the agent used. A randomized trial of aromatherapy with patients who reported nausea in the postanesthesia care unit was conducted at one ambulatory surgical center. Eligibility criteria were adult, able to give consent, and no history of coagulation problems or allergy to the aromatherapy agents. Before surgery, demographic and risk factors were collected. Patients with a nausea level of 1 to 3 on a verbal descriptive scale (0-3) received a gauze pad saturated with a randomly chosen aromatherapy agent and were told to inhale deeply 3 times; nausea (0-3) was then measured again in 5 minutes. Prophylactic and postnausea antiemetics were given as ordered by physicians or as requested by the patient. A total of 1151 subjects were screened for inclusion; 303 subjects reporting nausea were enrolled (26.3%), and 301 meeting protocol were analyzed (26.2%). The change in nausea level was significant for the blend (P < 0.001) and ginger (P = 0.002) versus saline but not for alcohol (P < 0.76). The number of antiemetic medications requested after aromatherapy was also significantly reduced with ginger or blend aromatherapy versus saline (P = 0.002 and P < 0.001, respectively). The hypothesis that aromatherapy would be effective as a treatment for PON was supported. On the basis of our results, future research further evaluating aromatherapy is warranted. Aromatherapy is promising as an inexpensive, noninvasive treatment for PON that can be administered and controlled by patients as needed.

Low protective PON1 lactonase activity in an Arab population with high rates of coronary heart disease and diabetes.

PubMed

Gugliucci, A; Caccavello, R; Nassar, H; Abu Ahmad, W; Sinnreich, R; Kark, J D

2015-05-20

Recent studies showing that high density lipoproteins (HDL) can effect plaque regression indicate that recent trial failures do not exclude an atheroprotective role of HDL. Instead, they highlight differences between HDL function and measured HDL-cholesterol (HDL-C). PON1 is one key functional activity of HDL. Urban Palestinians have lower HDL-C and a higher incidence and mortality of coronary heart disease than those of Israelis. We hypothesized that the cardioprotective PON1 lactonase and arylesterase activities and PON1 functional genotype may differ between Palestinians and Israelis. We measured PON1 activities in a cross-sectional population-based study of Palestinian (n=960) and Israeli (n=694) residents in Jerusalem, 1654 participants in all. Palestinians had high prevalences of obesity and diabetes and low mean concentrations of HDL-cholesterol (0.97 mmol/l in men and 1.19 mmol/l in women). Lactonase and arylesterase activities were lower by 10.8% (p=1.2∗10(-14)) and 2.7% (p<0.0005), respectively, in Palestinians as compared to Israelis. The functional genotype distribution, demonstrated by plotting paraoxonase vs lactonase activities, showed a modest between-group difference (p=0.024), with 12.1% RR in Palestinian Arabs vs 8.4% in Israeli Jews, but no overall difference in allele frequencies. Lactonase correlated inversely with age (Spearman's rho=-.156), weakly with BMI (-.059), positively with HDL-C (.173) and non-HDL-C (.103), but was not associated with triglycerides or fasting glucose. Palestinians showed consistently lower lactonase activity in logistic regression models adjusted for multiple covariates and for functional genotype (odds ratios of 1.81 and 1.98, respectively, for the lower fifth vs the upper 4 fifths of lactonase activity p<0.0001). We showed a lower physiologically-significant lactonase PON1 activity in an Arab population, a finding consistent with the high cardiovascular and diabetes risk of Palestinians. Copyright © 2015 Elsevier B.V. All rights reserved.

Paraoxonase 1 polymorphisms and haplotypes and the risk for having offspring affected with spina bifida in Southeast Mexico.

PubMed

Gonzalez-Herrera, Lizbeth; Martín Cerda-Flores, Ricardo; Luna-Rivero, Marianne; Canto-Herrera, Jorge; Pinto-Escalante, Doris; Perez-Herrera, Norma; Quintanilla-Vega, Betzabet

2010-11-01

Spina bifida (SB) is a common congenital malformation in Southeast Mexico. Parents of children with SB reside in areas with frequent pesticide spraying or have agriculture activities, suggesting potential exposure to pesticides. Paraoxonase 1 (PON1) is the responsible enzyme for deactivation of organophosphates (OP) in the central nervous system. Polymorphisms of PON1 genes influence the catalytic activity and plasma protein level of the enzyme, therefore, genotypic characterization of PON1 gene represents a potential predictor for susceptibility to OP-related effects. The frequency of PON1 haplotypes and polymorphisms (-108CT, L55M, and Q192R) were determined in this study. A case-control study was performed to evaluate the risk for having offspring affected by SB in 152 cases and 160 control parents. Polymorphisms were determined by PCR amplification and restriction fragment length polymorphism and Real Time-PCR. Odds ratios and confidence interval 95% were estimated. Genotype frequencies for the three PON1 polymorphisms were distributed according to Hardy-Weinberg expectations (p > 0.05) and were significantly different between cases and controls (p < 0.05). The heterozygous CT genotype of -108CT polymorphism, the RR genotype of Q192R polymorphism, both LM and MM genotypes of L55M polymorphism, and the haplotypes 221 and 222 (for -108CT, L55M, and Q192R) were associated with the risk for having a child affected by SB (p < 0.02). The heterozygous -108CT genotype was associated only maternally, whereas the heterozygous L55M genotype was relevant only in the fathers. The RR homozygous genotype was relevant both in mothers and fathers, suggesting the importance of this substrate-specific polymorphism. Results suggest that PON1 polymorphisms are relevant risk factors for having offspring affected with SB in this population from Southeast Mexico. © 2010 Wiley-Liss, Inc.

Paraoxonase gene Q192R & L55M polymorphisms in Indians with acute myocardial infarction & association with oxidized low density lipoprotein.

PubMed

Lakshmy, Ramakrishnan; Ahmad, Dilawar; Abraham, Rani Ann; Sharma, Mukta; Vemparala, Kranthi; Das, Siuli; Reddy, K Srinath; Prabhakaran, Dorairaj

2010-04-01

Paraoxonase (PON) is an HDL associated ester hydrolase with an ability to retard LDL oxidation in vitro by preventing lipid peroxide generation. The population variability in enzyme activity is attributed to polymorphisms in paraoxonase gene. For example, polymorphism at codon 192 and 55 of the paraoxonase gene has been reported to be associated with coronary heart disease (CAD) and diabetes among different ethnic groups. The present study looks at PON192 and 55 polymorphism among hospitalized Asian Indian patients with myocardial infarction (MI) and their association with circulating oxidized LDL and antioxidant status. One hundred and twenty four consecutive patients of acute myocardial infarction and 221 age-matched controls were recruited for the study. Oxidized LDL was measured in serum by ELISA and total antioxidant levels by the 2,2'-azino-bis-(3 ethyl benzothiozoline-6-sulfonate) (ABTS) method. Other known cardiovascular risk factors, apolipoprotein B, apolipoproteinA1, lipoprotein(a), hsCRP and homocysteine were also measured. Paraoxonase gene polymorphism at codon 192 and 55 were analyzed by PCR-RFLP. Patients with MI had significantly higher oxidized LDL (P<0.05) and lower total antioxidant capacity (P<0.001) as compared to controls. Oxidized LDL correlated with total cholesterol, LDL and Apo B in patients. B allele frequency of the codon 192 polymorphism in paraoxonase gene was higher in cases as compared to controls and odds ratio of developing the MI with BB genotype versus AA genotype was 2.37, (P=0.044). Codon 55 polymorphism in paraoxonase gene was not associated with CAD. There was no difference in oxidized LDL between the different genotypes of PON192 and PON55. Although PON192 polymorphism was associated with CAD, no correlation of PON192 or 55 polymorphism was found with oxidized LDL suggesting that presence of other antioxidant factors may be of equal importance in preventing LDL oxidation.

The rs662 polymorphism of paraoxonase 1 affects the difference in the inhibition of butyrylcholinesterase activity by organophosphorus pesticides in human blood.

PubMed

Nam, Dae Cheol; Ha, Yu Mi; Park, Min Kyu; Cho, Sung Kweon

2016-08-01

Organophosphorus pesticides (OPs) are a human health hazard. OPs inhibit acetylcholinesterase (AChE) at nerve endings and accumulate acetylcholine (ACh) at these sites. High levels of ACh and long exposure promote cholinergic crisis. The hydrolysis of OPs by serum paraoxonase 1 (PON1) plays a role in cholinergic crisis in humans. Human serum PON1 can break down organophosphate before binding to ChE. We investigated the effect of PON1 polymorphisms on AChE activity after OP treatment. 50 healthy volunteers were randomly recruited with informed consent. We investigated butyrylcholinesterase (BuChE) activity changes in plasma as a biomarker of AChE after OP treatment in human blood samples immediately following blood sampling. After the standardization of BuChE activity in human blood, we correlated changes in BuChE activity with changes in blood pH. We analyzed the PON1 polymorphisms (rs854560 and rs662) of 50 participants to retrospectively investigate the interindividual variability of changes in BuChE activity. Changes in BuChE activity are strongly correlated with pH changes after OP treatment (R2 = 0.913). We used changes in pH as a surrogate marker for BuChE inhibition after OP treatment. OP treatment significantly decreased BuChE activity by 56.4 ± 5.1% (p < 0.001). The degree of BuChE inhibition was significantly different in the PON1 rs662 genotype (56.10 ± 4.74% vs. 57.96 ± 5.67% vs. 52.34 ± 1.51%; GG vs. GA vs. AA, respectively). Changes in pH can be used as a surrogate marker for the detection of BuChE inhibition after OP exposure. The rs662 polymorphism of PON1 may explain the inter-individual variability in BuChE inhibition.

Network coding based joint signaling and dynamic bandwidth allocation scheme for inter optical network unit communication in passive optical networks

NASA Astrophysics Data System (ADS)

Wei, Pei; Gu, Rentao; Ji, Yuefeng

2014-06-01

As an innovative and promising technology, network coding has been introduced to passive optical networks (PON) in recent years to support inter optical network unit (ONU) communication, yet the signaling process and dynamic bandwidth allocation (DBA) in PON with network coding (NC-PON) still need further study. Thus, we propose a joint signaling and DBA scheme for efficiently supporting differentiated services of inter ONU communication in NC-PON. In the proposed joint scheme, the signaling process lays the foundation to fulfill network coding in PON, and it can not only avoid the potential threat to downstream security in previous schemes but also be suitable for the proposed hybrid dynamic bandwidth allocation (HDBA) scheme. In HDBA, a DBA cycle is divided into two sub-cycles for applying different coding, scheduling and bandwidth allocation strategies to differentiated classes of services. Besides, as network traffic load varies, the entire upstream transmission window for all REPORT messages slides accordingly, leaving the transmission time of one or two sub-cycles to overlap with the bandwidth allocation calculation time at the optical line terminal (the OLT), so that the upstream idle time can be efficiently eliminated. Performance evaluation results validate that compared with the existing two DBA algorithms deployed in NC-PON, HDBA demonstrates the best quality of service (QoS) support in terms of delay for all classes of services, especially guarantees the end-to-end delay bound of high class services. Specifically, HDBA can eliminate queuing delay and scheduling delay of high class services, reduce those of lower class services by at least 20%, and reduce the average end-to-end delay of all services over 50%. Moreover, HDBA also achieves the maximum delay fairness between coded and uncoded lower class services, and medium delay fairness for high class services.

Development and psychometric properties of the parent version of the Profile of Neuropsychiatric Symptoms (PONS) in children and adolescents.

PubMed

Santosh, Paramala; Gringras, Paul; Baird, Gillian; Fiori, Federico; Sala, Regina

2015-05-19

The use of neuropsychiatric Patient Centred Outcome Measures (PCOMs) in routine child mental health and paediatric services is very time consuming and often requires multiple scales being completed as no single scale covers all areas of psychopathology. The use of a web-based programme can overcome these problems and contribute to improved use of PCOMs in clinical practice. We aim to develop a web-based scale (using HealthTracker™) to screen and identify young people with significant neuropsychiatric symptoms to enable early intervention. Qualitative development of the Profile of Neuropsychiatric Symptoms (PONS) and quantitative evaluation of the psychometric properties of the PONS scale (parent version). Parents of 929 from the general population and 147 with neuropsychiatric disorders (5-18 years old) completed the PONS online. In addition, those children with neuropsychiatric disorders were assessed for the presence of current and lifetime psychiatric disorders using the Development and Well-Being Assessment (DAWBA). The PONS scale (parent version) consists of 30 symptom domains rated on a 7-point scale for both frequency and impairment. We found an intra-class correlation coefficient for single measures was 0.44 (0.42-0.46 95 % CI, F = 22.84, p ≤ 0.0001) and for average measures was 0.96 (0.95-0.96 95 % CI, F = 22.84, p ≤ 0.0001). The factor analysis showed a 4-factor model: Neurodevelopmental Disability; Behavioural and Emotional Dysregulation; Psychoses and Personality Dysfunction; and Anxiety and Depression. The receiver operating characteristic area for the 4-factors was 0.96 (SE = 0.006; 0.95-0.97 95 % CI). The PONS scale (parent version) is a web-based PCOM on the HealthTracker™ system that is a rapid, engaging measure that has excellent reliability and validity. The system allows for automated scoring and immediate feedback of statistical cut-off points and assists clinicians with diagnostic decision-making and optimises use of clinician time.

Oxidative status and serum PON1 activity in beta-thalassemia minor.

PubMed

Selek, Sahbettin; Aslan, Mehmet; Horoz, Mehmet; Gur, Mustafa; Erel, Ozcan

2007-03-01

Paraoxonase-1 (PON1) deficiency is related to increased susceptibility to low density lipoprotein oxidation and development of atherosclerosis. The aim of this study was to investigate paraoxonase and arylesterase activities along with oxidative status parameters, and to find out if there is any increased susceptibility to atherogenesis, which might be reflected with increased oxidative stress and decreased serum PON1 activity in beta-thalassemia minor (BTM) subjects. Thirty-two subjects with BTM and 28 healthy subjects as control were enrolled in the study. Serum paraoxonase and arylesterase activities, lipid hydroperoxide (LOOH) levels, total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined. Serum TAC, paraoxonase and arylesterase activities were significantly lower in BTM subjects than controls (for all p<0.001), while TOS, LOOH levels and OSI were significantly higher (p<0.001, p<0.05 and p<0.001; respectively). In BTM subjects, OSI, TOS, LOOH levels and TAC were significantly correlated with serum paraoxonase (r=-0.245, p<0.05; r=-0.231, p<0.05; r=-0.264, p<0.05 and, r=0.342, p<0.05, respectively) and arylesterase activities (r=-0.332, p<0.05, r=-0.308, p<0.05; r=-0.320, p<0.05 and r=0.443, p<0.05). Additionally, hemoglobin level was also correlated with serum paraoxonase (r=0.501, p<0.001) and arylesterase activities (r=0.501, p<0.001), TAC (r=0.402, p<0.05), TOS (r=-0.274, p<0.05) and OSI (r=-0.352, p<0.05). Oxidative stress is increased, while serum PON1 activity is decreased in BTM subjects. Decrease in PON1 activity seems to be associated with both the degree of oxidative stress and anemia. BTM subjects may be more prone to development of atherogenesis due to low serum PON1 activity.

Serum paraoxonase-1 as biomarker for improved diagnosis of fatty liver in dairy cows.

PubMed

Farid, Ayman Samir; Honkawa, Kazuyuki; Fath, Eman Mohamed; Nonaka, Nariaki; Horii, Yoichiro

2013-04-11

Fatty liver is a major metabolic disorder in dairy cows and is believed to result in major economic losses in dairy farming due to decreased health status, reproductive performance and fertility. Currently, the definitive means for diagnosing fatty liver is determining the fat content of hepatic tissue by liver biopsy, which is an invasive and costly procedure, making it poorly suited to dairy farms. Therefore, the key aim of this study was to investigate the measurement of serum paraoxonase-1 (PON1), an enzyme exclusively synthesized by the liver, as a sensitive noninvasive biomarker for diagnosis of fatty liver in dairy cows. A comparative cohort study using serum specimens from Holstein-Friesian dairy cows (46 healthy and 46 fatty liver cases) was conducted. Serum PON1 (paraoxonase, lactonase and arylesterase) activity and other biochemical and hematological parameters were measured. We found that serum PON1 activity was lower (P<0.001) in cows suffering from fatty liver. The area under the receiver operating characteristic curve (AUC-ROC) of PON1 activity for diagnosis of fatty liver was 0.973-0.989 [95% confidence interval (CI) 0.941, 1.000] which was higher than the AUC-ROC of aspartate aminotransferase (AST), lecithin-cholesterol acyltransferase (LCAT), alkaline phosphatase (ALP), non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL). We found that adding serum PON1 measurement to different batteries of serum diagnostic panels showed a combination of high sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), negative likelihood ratio (-LR), diagnostic odd ratio (DOR) and overall diagnostic accuracy in diagnosing fatty liver. The present results indicate that addition of serum PON1 activity measurement to the biochemical profile could improve the diagnosis of fatty liver in dairy cows, which would have a considerable clinical impact and lead to greater profitability in the dairy industry.

Polymorphisms of pesticide-metabolizing genes in children living in intensive farming communities.

PubMed

Gómez-Martín, Antonio; Hernández, Antonio F; Martínez-González, Luis Javier; González-Alzaga, Beatriz; Rodríguez-Barranco, Miguel; López-Flores, Inmaculada; Aguilar-Garduno, Clemente; Lacasana, Marina

2015-11-01

Polymorphisms in genes encoding xenobiotic-metabolizing enzymes (XME) are important parameters accounting for the wide inter-individual variability to environmental exposures. Paraoxonase-1 (PON1), butyrylcholinesterase (BChE) and Cytochrome-P450 constitute major classes of XME involved in the detoxification of pesticide chemicals, in particular organophosphates. This study explored the allelic frequency, linkage disequilibrium and haplotype analysis of ten common polymorphic variants of seven key genes involved in organophosphate metabolism (BCHE-K, BCHE-A, PON1 Q192R, PON1 L55M, PON1 -108C/T, CYP2C19 G681A, CYP2D6 G1846A, CYP3AP1 -44G/A, GSTM1∗0 and GSTT1∗0) in a children population living near an intensive agriculture area in Spain. It was hypothesized that individuals with unfavorable combinations of gene variants will be more susceptible to adverse effects from organophosphate exposure. Genomic DNA from 496 healthy children was isolated and amplified by PCR. Hydrolysis probes were used for the detection of eight specific SNPs and two copy number variants (CNVs) by using TaqMan® Assay-based real-time PCR. Frequencies of SNPs and CNVs in the target genes were in Hardy-Weinberg equilibrium and broadly consistent with European populations. Linkage disequilibrium was found between the three PON1 genetic polymorphisms studied and between BCHE-K and BCHE-A. The adverse genotype combination (unusual BCHE variants, PON1 55MM/-108TT and null genotype for both GSTM1 and GSTT1) potentially conferring a greater genetic risk from exposure to organophosphates was observed in 0.2% of our study population. This information allows broadening our knowledge about differential susceptibility toward environmental toxicants and may be helpful for further research to understand the inter-individual toxicokinetic variability in response to organophosphate pesticides exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

A novel protection scheme for a hybrid WDM/TDM PON

NASA Astrophysics Data System (ADS)

Chen, Jiajia; Wosinska, Lena; He, Sailing

2007-11-01

This paper proposes a novel protection scheme based on the cyclic property of an array waveguide grating (AWG) and neighboring connection pattern between two adjacent optical network units (ONUs) for the hybrid WDM/TDM passive optical networks (PONs). Our scheme uses 50% fewer wavelengths while offering one order of magnitude better connection availability than the existing scheme.

AmeriFlux US-Pon Ponca City

DOE Data Explorer

Verma, Shashi [University of Nebraska - Lincoln

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Pon Ponca City. Site Description - The Ponca Winter Wheat site is a 65 ha rainfed wheat field in north central Oklahoma. Planting of winter wheat takes place annually in mid-fall. By late May, most of the wheat reaches maturity, allowing for mid-summer harvest.

Distribution of genetic variants of oxidative stress metabolism genes: Paraoxonase 1 (PON1) and Glutathione S-transferase (GSTM1/GSTT1) in a population from Southeastern Mexico.

PubMed

García-González, I; Mendoza-Alcocer, R; Pérez-Mendoza, G J; Rubí-Castellanos, R; González-Herrera, L

2016-11-01

Paraoxonase 1 (PON1) and glutathione S-transferases (GSTs) are involved in the biotransformation of xenobiotics. Variation in the enzyme concentration and activity suggests individual differences for the degree of protection against oxidative stress. This study analysed the distribution of SNPs Q192R, L55M (PON1) and variants in GSTM1 and GSTT1 genes in a population from Southeastern Mexico. One hundred and fifty-one Mexican Mestizo healthy volunteers were included. PON1 polymorphisms were determined by Taqman allele discrimination real time-PCR, whereas GSTM1 and GSTT1 genes were determined with a multiplex PCR-based method. All genotypes were in Hardy-Weinberg equilibrium, except for GSTM1. The genotypic distributions of Q192R and L55M were 22% QQ, 48% QR, 30% RR, 62% LL, 34% LM and 4% MM, respectively, whereas the allele frequencies were 0.46 (Q), 0.54 (R), 0.79 (L) and 0.21 (M). The most frequent haplotype was R/L (46.7%). It was found that 31% and 9% of the individuals had the GSTM1 and GSTT1 null genotype, respectively. The frequency of the combined null genotype GSTM1*0/GSTT1*0 was 4.64%. The results showed that the frequencies of polymorphisms of PON1, GSTM1 and GSTT1 in the Yucatán population differ to those observed in other ethnic groups and provide useful data for epidemiological studies.

High morning blood pressure surge is associated with oxidative stress and paraoxonase 1 activity in newly diagnosed hypertensive patients.

PubMed

Kaypaklı, Onur; Gür, Mustafa; Harbalıoğlu, Hazar; Şeker, Taner; Selek, Şahabettin

Both oxidative stress and morning surge (MS) of blood pressure (BP) were found to be closely related with cardiovascular and cerebrovascular diseases. We investigated the association between MS of BP and oxidative stress in newly diagnosed hypertensive patients. We prospectively included 237 newly diagnosed hypertensive patients in the present study (mean age: 51.6 ± 11.7 years). The patients were classified according to the extent of the sleep-through surge as follows: the top decile of sleep-through surge (>47.2 mmHg, n = 27; EMShigh group), versus all others (n = 210, EMSlow group). Total antioxidant capacity (TAC) and total oxidant status (TOS) levels were determined by using an automated measurement method. The oxidative stress index (OSI) was calculated as the ratio of TOS to TAC. Serum paraoxonase 1 (PON-1) activity was measured spectrophotometrically. Patients in EMShigh group were found to have higher hs-CRP, TOS, and OSI values and lower TAC and PON-1 values (p < 0.01, for all). MS of BP was associated with hs-CRP, PON-1, TOS, TAC, and OSI levels in bivariate analysis. Multivariate linear regression analysis showed that MS of BP was significantly associated with PON-1(β = -0.206, p < 0.001), OSI (β = 0.602, p < 0.001) and hs-CRP (β = 0.210, p < 0.001). Present study shows that OSI is increased and antioxidant PON-1 activity is decreased in patients with enhanced MS of BP. There is a close association between high MS of BP and oxidative stress markers in newly diagnosed hypertensive patients.

Insights into the Lactonase Mechanism of Serum Paraoxonase 1 (PON1): Experimental and Quantum Mechanics/Molecular Mechanics (QM/MM) Studies.

PubMed

Le, Quang Anh Tuan; Kim, Seonghoon; Chang, Rakwoo; Kim, Yong Hwan

2015-07-30

Serum paraoxonase 1 (PON1) is a versatile enzyme for the hydrolysis of various substrates (e.g., lactones, phosphotriesters) and for the formation of a promising chemical platform γ-valerolactone. Elucidation of the PON1-catalyzed lactonase reaction mechanism is very important for understanding the enzyme function and for engineering this enzyme for specific applications. Kinetic study and hybrid quantum mechanics/molecular mechanics (QM/MM) method were used to investigate the PON1-catalyzed lactonase reaction of γ-butyrolactone (GBL) and (R)-γ-valerolactone (GVL). The activation energies obtained from the QM/MM calculations were in good agreement with the experiments. Interestingly, the QM/MM energy barriers at MP2/3-21G(d,p) level for the lactonase of GVL and GBL were respectively 14.3-16.2 and 11.5-13.1 kcal/mol, consistent with the experimental values (15.57 and 14.73 kcal/mol derived from respective kcat values of 36.62 and 147.21 s(-1)). The QM/MM energy barriers at MP2/6-31G(d) and MP2/6-31G(d,p) levels were also in relatively good agreements with the experiments. Importantly, the difference in the QM/MM energy barriers at MP2 level with all investigated basis sets for the lactonase of GVL and GBL were in excellent agreement with the experiments (0.9-3.1 and 0.8 kcal/mol, respectively). A detailed mechanism for the PON1-catalyzed lactonase reaction was also proposed in this study.

A pilot study assessing the association between paraoxonase 1 gene polymorphism and prostate cancer.

PubMed

Uluocak, Nihat; Atılgan, Doğan; Parlaktaş, Bekir Süha; Erdemir, Fikret; Ateş, Ömer

2017-09-01

We aimed to show the relationship between paraoxonase 1 (PON1) gene polymorphism and the development of prostate cancer (PCa). We investigated the association of single nuclotide polymorphisms of PON1 enzyme with the development of PCa risk. A total of 147 male patients were divided into PCa, and control groups. The control group was also divided into two subgroups according to serum prostate specific antigen (PSA) levels as non PCa-high PSA (>4 ng/mL) and non PCa-low PSA (≤4 ng/mL) groups. The mean ages of the patients were 64.81 years, 63.27 years and 64.22 years in PCa group, non PCa-low PSA and non PCa -high PSA groups, respectively. The mean PSA levels were 10.9 ng/mL, 1.16 ng/mL and 6.63 ng/mL for PCa group, non PCa -low PSA and non PCa -high PSA groups, respectively. In terms of PON1 polymorphisms and allele frequencies, there were no statistically significant differences between PCa and control groups. There was not a statistically significant difference between PCa and non PCa-high PSA groups as for genotypic and allelic frequencies. As a result of this small sample sized hypothetical study of polymorphism, a relationship could not be detected between PCa development and PON1 gene polymorphism. According to the results of this preliminary study, it is thought that more comprehensive future studies are necessary to clarify the possible role of PON1 gene polymorphism in the etiology of PCa.

Association of paraoxonase gene cluster polymorphisms with ALS in France, Quebec, and Sweden.

PubMed

Valdmanis, P N; Kabashi, E; Dyck, A; Hince, P; Lee, J; Dion, P; D'Amour, M; Souchon, F; Bouchard, J-P; Salachas, F; Meininger, V; Andersen, P M; Camu, W; Dupré, N; Rouleau, G A

2008-08-12

The paraoxonase gene cluster on chromosome 7 comprising the PON1-3 genes is an attractive candidate for association in amyotrophic lateral sclerosis (ALS) given the role of paraoxonase genes during the response to oxidative stress and their contribution to the enzymatic break down of nerve toxins. Oxidative stress is considered one of the mechanisms involved in ALS pathogenesis. Evidence for this includes the fact that mutations of SOD1, which normally reduce the production of toxic superoxide anion, account for 12% to 23% of familial cases in ALS. In addition, PON variants were shown to be associated with susceptibility to ALS in several North American and European populations. We extended this analysis to examine 20 single nucleotide polymorphisms (SNPs) across the PON gene cluster in a set of patients from France (480 cases, 475 controls), Quebec (159 cases, 95 controls), and Sweden (558 cases, 506 controls). Although individual SNPs were not considered associated on their own, a haplotype of SNPs at the C-terminal portion of PON2 that includes the PON2 C311S amino acid change was significant in the French (p value 0.0075) and Quebec (p value 0.026) populations as well as all three populations combined (p value 1.69 x 10(-6)). Stratification of the samples showed that this variation was pertinent to ALS susceptibility as a whole, and not to a particular subset of patients. These findings contribute to the increasing weight of evidence that genetic variants in the paraoxonase gene cluster are associated with amyotrophic lateral sclerosis.

A pilot study assessing the association between paraoxonase 1 gene polymorphism and prostate cancer

PubMed Central

Uluocak, Nihat; Atılgan, Doğan; Parlaktaş, Bekir Süha; Erdemir, Fikret; Ateş, Ömer

2017-01-01

Objective We aimed to show the relationship between paraoxonase 1 (PON1) gene polymorphism and the development of prostate cancer (PCa). Material and methods We investigated the association of single nuclotide polymorphisms of PON1 enzyme with the development of PCa risk. A total of 147 male patients were divided into PCa, and control groups. The control group was also divided into two subgroups according to serum prostate specific antigen (PSA) levels as non PCa-high PSA (>4 ng/mL) and non PCa-low PSA (≤4 ng/mL) groups. Results The mean ages of the patients were 64.81 years, 63.27 years and 64.22 years in PCa group, non PCa-low PSA and non PCa –high PSA groups, respectively. The mean PSA levels were 10.9 ng/mL, 1.16 ng/mL and 6.63 ng/mL for PCa group, non PCa –low PSA and non PCa –high PSA groups, respectively. In terms of PON1 polymorphisms and allele frequencies, there were no statistically significant differences between PCa and control groups. There was not a statistically significant difference between PCa and non PCa-high PSA groups as for genotypic and allelic frequencies. As a result of this small sample sized hypothetical study of polymorphism, a relationship could not be detected between PCa development and PON1 gene polymorphism. Conclusion According to the results of this preliminary study, it is thought that more comprehensive future studies are necessary to clarify the possible role of PON1 gene polymorphism in the etiology of PCa. PMID:28861298

The platelet activating factor acetyl hydrolase, oxidized low-density lipoprotein, paraoxonase 1 and arylesterase levels in treated and untreated patients with polycystic ovary syndrome.

PubMed

Carlioglu, Ayse; Kaygusuz, Ikbal; Karakurt, Feridun; Gumus, Ilknur Inegol; Uysal, Aysel; Kasapoglu, Benan; Armutcu, Ferah; Uysal, Sema; Keskin, Esra Aktepe; Koca, Cemile

2014-11-01

To evaluate the platelet activating factor acetyl hydrolyze (PAF-AH), oxidized low-density lipoprotein (ox-LDL), paraoxonase 1 (PON1), arylesterase (ARE) levels and the effects of metformin and Diane-35 (ethinyl oestradiol + cyproterone acetate) therapies on these parameters and to determine the PON1 polymorphisms among PCOS patients. Ninety patients with PCOS, age 30, and body mass index-matched healthy controls were included in the study. Patients were divided into three groups: metformin treatment, Diane-35 treatment and no medication groups. The treatment with metformin or Diane-35 was continued for 6 months and all subjects were evaluated with clinical and biochemical parameters 6 months later. One-way Anova test, t test and non-parametric Mann-Whitney U tests were used for statistical analysis. PAF-AH and ox-LDL levels were statistically significantly higher in untreated PCOS patients than controls, and they were statistically significantly lower in patients treated with metformin or Diane-35 than untreated PCOS patients. In contrast, there were lower PON1 (not statistically significant) and ARE (statistically significant) levels in untreated PCOS patients than the control group and they significantly increased after metformin and Diane-35 treatments. In PCOS patients serum PON1 levels for QQ, QR and RR phenotypes were statistically significantly lower than the control group. In patients with PCOS, proatherogenic markers increase. The treatment of PCOS with metformin or Diane-35 had positive effects on lipid profile, increased PON1 level, which is a protector from atherosclerosis and decreased the proatherogenic PAF-AH and ox-LDL levels.

10Gbps monolithic silicon FTTH transceiver without laser diode for a new PON configuration.

PubMed

Zhang, Jing; Liow, Tsung-Yang; Lo, Guo-Qiang; Kwong, Dim-Lee

2010-03-01

A new passive optical network (PON) configuration and a novel silicon photonic transceiver architecture for optical network unit (ONU) are proposed, eliminating the need for an internal laser source in ONU. The Si transceiver is fully monolithic, includes integrated wavelength division multiplexing (WDM) filters, modulators (MOD) and photo-detectors (PD), and demonstrates low-cost high volume manufacturability.

128 Gb/s TWDM PON system using dispersion-supported transmission method

NASA Astrophysics Data System (ADS)

Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, Abusahmah M.; Idrus, Sevia M.; Salleh, M. S.

2017-11-01

Time and wavelength division multiplexed passive optical network (TWDM-PON) trend is considered as the most extraordinary trend of the next generation solution to accommodate exponential traffic growth for converged new services. In this paper, we briefly review recent progress on TWDM-PON system through the use of low cost directly modulated lasers (DMLs) transmission for various line rate transmissions to date. Furthermore, through simulation, we propose and evaluate a cost effective way to upgrade TWDM-PON up to a symmetric capacity of 128 Gb/s using fiber Bragg gratings (FBGs) in optical line terminal (OLT) as a paramount dispersion manager in high speed light-wave systems in both upstream and downstream directions. A low cost and potential chirpless directed modulated grating laser (DMGL) is employed for downstream link and DML with a single delay-interferometer (DI) is employed for upstream link. After illustrating the demonstrated system architecture and configuration, we present the results and analysis to prove the system feasibility. The results show that a successful transmission is achieved over 40 km single mode fiber with a power budget of 33.7 dB, which could support 1:256 splitting ratio.

Carbon and nitrogen cycling in the Zhubi coral reef lagoon of the South China Sea as revealed by 210Po and 210Pb.

PubMed

Yang, W F; Huang, Y P; Chen, M; Qiu, Y S; Li, H B; Zhang, L

2011-05-01

The radionuclides (210)Po and (210)Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14 mg Cm(-2) d(-1). However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from (210)Po/(210)Pb disequilibria, are 43 mg Cm(-2) d(-1) and 13.8 mg Nm(-2) d(-1), respectively. The deficit of (210)Po relative to (210)Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310 mg Cm(-2) d(-1) and 121 mg Nm(-2) d(-1) were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30 m(-1), respectively. Thus, (210)Po and (210)Pb can quantify the cycling of carbon and nitrogen in this coral lagoon. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Effect of Agoraphobia on Oxidative Stress in Panic Disorder

PubMed Central

Karlidag, Rifat; Cumurcu, Birgul Elbozan; Turkoz, Yusuf; Kartalci, Sukru; Ozcan, A. Cemal; Erdemli, M. Erman

2013-01-01

We aimed to investigate whether agoraphobia (A) in panic disorder (PD) has any effects on oxidative and anti-oxidative parameters. We measured total antioxidant capacity (TAC), paraoxonase (PON), arylesterase (ARE) antioxidant and malondialdehyde (MDA) oxidant levels using blood samples from a total of 31 PD patients with A, 22 PD patients without A and 53 control group subjects. There was a significant difference between the TAC, PON, ARE and MDA levels of the three groups consisting of PD with A, PD without A and the control group. The two-way comparison to clarify the group creating the difference showed that the TAC, PON, and ARE antioxidants were significantly lower in the PD with A group compared to the control group while the MDA oxidant was significantly higher. There was no significant difference between the PD without A and control groups for TAC, PON, ARE and MDA levels. We clearly demonstrated that the oxidative stress and damage to the anti-oxidative mechanism are significantly higher in the PD group with A. These findings suggest that oxidative/anti-oxidative mechanisms may play a more important role on the pathogenesis of PB with A. PMID:24474979

Paraoxonase-1 gene Q192R polymorphism and reactive oxygen metabolites.

PubMed

Kotani, K; Tsuzaki, K; Sakane, N

2012-01-01

Paraoxonase-1 (PON1) is a high-density lipoprotein-associated antioxidant enzyme. The Q192R polymorphism of the PON1 gene can protect against oxidative conditions, but the relationship between Q192R polymorphism and oxidative stress-related markers remains controversial. In this study, the diacron reactive oxygen metabolites (d-ROMs) test was used to investigate the relationship between Q192R polymorphism and oxidative stress-related markers in Japanese subjects. Patients without a history of overt cardiovascular disease who were not receiving antioxidant medication were enrolled in a cross-sectional clinic-based study. An allele-specific polymerase chain reaction method was used to assess the PON1 Q192R polymorphism and compare the level of d-ROMs between genotypes. A total of 103 subjects were analysed. The RR genotype was associated with a significantly lower level of d-ROMs than the RQ and QQ genotypes. After multivariate analysis the relationship between the genotypes and level of d-ROMs remained independently significant. The RR genotype may be protective against oxidative stress in cardiovascular diseasefree Japanese subjects. In addition, the d-ROMs test can be useful for examining the role of the PON1 Q192R polymorphism under oxidative conditions.

A Functional Polymorphism of the MAOA Gene Modulates Spontaneous Brain Activity in Pons

PubMed Central

Lei, Hui; Zhang, Xiaocui; Di, Xin; Rao, Hengyi; Ming, Qingsen; Zhang, Jibiao; Guo, Xiao; Jiang, Yali; Gao, Yidian; Yi, Jinyao; Zhu, Xiongzhao; Yao, Shuqiao

2014-01-01

Objective. To investigate the effects of a functional polymorphism of the monoamine oxidase A (MAOA) gene on spontaneous brain activity in healthy male adolescents. Methods. Thirty-one healthy male adolescents with the low-activity MAOA genotype (MAOA-L) and 25 healthy male adolescents with the high-activity MAOA genotype (MAOA-H) completed the 11-item Barratt Impulsiveness Scale (BIS-11) questionnaire and were subjected to resting-state functional magnetic resonance imaging (rs-fMRI) scans. The amplitude of low-frequency fluctuation (ALFF) of the blood oxygen level-dependent (BOLD) signal was calculated using REST software. ALFF data were related to BIS scores and compared between genotype groups. Results. Compared with the MAOA-H group, the MAOA-L group showed significantly lower ALFFs in the pons. There was a significant correlation between the BIS scores and the ALFF values in the pons for MAOA-L group, but not for the MAOA-H group. Further regression analysis showed a significant genotype by ALFF values interaction effect on BIS scores. Conclusions. Lower spontaneous brain activity in the pons of the MAOA-L male adolescents may provide a neural mechanism by which boys with the MAOA-L genotype confers risk for impulsivity and aggression. PMID:24971323

A functional polymorphism of the MAOA gene modulates spontaneous brain activity in pons.

PubMed

Lei, Hui; Zhang, Xiaocui; Di, Xin; Rao, Hengyi; Ming, Qingsen; Zhang, Jibiao; Guo, Xiao; Jiang, Yali; Gao, Yidian; Yi, Jinyao; Zhu, Xiongzhao; Yao, Shuqiao

2014-01-01

To investigate the effects of a functional polymorphism of the monoamine oxidase A (MAOA) gene on spontaneous brain activity in healthy male adolescents. Thirty-one healthy male adolescents with the low-activity MAOA genotype (MAOA-L) and 25 healthy male adolescents with the high-activity MAOA genotype (MAOA-H) completed the 11-item Barratt Impulsiveness Scale (BIS-11) questionnaire and were subjected to resting-state functional magnetic resonance imaging (rs-fMRI) scans. The amplitude of low-frequency fluctuation (ALFF) of the blood oxygen level-dependent (BOLD) signal was calculated using REST software. ALFF data were related to BIS scores and compared between genotype groups. Compared with the MAOA-H group, the MAOA-L group showed significantly lower ALFFs in the pons. There was a significant correlation between the BIS scores and the ALFF values in the pons for MAOA-L group, but not for the MAOA-H group. Further regression analysis showed a significant genotype by ALFF values interaction effect on BIS scores. Lower spontaneous brain activity in the pons of the MAOA-L male adolescents may provide a neural mechanism by which boys with the MAOA-L genotype confers risk for impulsivity and aggression.

Efficient traffic grooming with dynamic ONU grouping for multiple-OLT-based access network

NASA Astrophysics Data System (ADS)

Zhang, Shizong; Gu, Rentao; Ji, Yuefeng; Wang, Hongxiang

2015-12-01

Fast bandwidth growth urges large-scale high-density access scenarios, where the multiple Passive Optical Networking (PON) system clustered deployment can be adopted as an appropriate solution to fulfill the huge bandwidth demands, especially for a future 5G mobile network. However, the lack of interaction between different optical line terminals (OLTs) results in part of the bandwidth resources waste. To increase the bandwidth efficiency, as well as reduce bandwidth pressure at the edge of a network, we propose a centralized flexible PON architecture based on Time- and Wavelength-Division Multiplexing PON (TWDM PON). It can provide flexible affiliation for optical network units (ONUs) and different OLTs to support access network traffic localization. Specifically, a dynamic ONU grouping algorithm (DGA) is provided to obtain the minimal OLT outbound traffic. Simulation results show that DGA obtains an average 25.23% traffic gain increment under different OLT numbers within a small ONU number situation, and the traffic gain will increase dramatically with the increment of the ONU number. As the DGA can be deployed easily as an application running above the centralized control plane, the proposed architecture can be helpful to improve the network efficiency for future traffic-intensive access scenarios.

A Novel Cost-effective OFDM WDM-PON Radio Over Fiber System Employing FBG to Generate Optical mm-wave

NASA Astrophysics Data System (ADS)

Nguyen, HoangViet

2015-03-01

We have investigated and demonstrated a novel scheme to generate 2.5 Gbit/s 64 QAM orthogonal frequency division multiplexing (OFDM) signals for Radio Over Fiber (ROF) systems. We employ Fiber Bragg Grating (FBG) because the repetitive frequency of the RF source and the bandwidth of the optical modulator are largely reduced and the architecture of the ROF system is simpler. Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) has been considered as a promising solution for future broadband access networks. Principle of WDM-PON access network compatible with OFDM-ROF systems is investigated. This novel scheme which has multiple double-frequency technique to generate mm-wave signal to carry OFDM signals is a practical scheme to be applied for future broadband access networks.

Tunable optical frequency comb enabled scalable and cost-effective multiuser orthogonal frequency-division multiple access passive optical network with source-free optical network units.

PubMed

Chen, Chen; Zhang, Chongfu; Liu, Deming; Qiu, Kun; Liu, Shuang

2012-10-01

We propose and experimentally demonstrate a multiuser orthogonal frequency-division multiple access passive optical network (OFDMA-PON) with source-free optical network units (ONUs), enabled by tunable optical frequency comb generation technology. By cascading a phase modulator (PM) and an intensity modulator and dynamically controlling the peak-to-peak voltage of a PM driven signal, a tunable optical frequency comb source can be generated. It is utilized to assist the configuration of a multiple source-free ONUs enhanced OFDMA-PON where simultaneous and interference-free multiuser upstream transmission over a single wavelength can be efficiently supported. The proposed multiuser OFDMA-PON is scalable and cost effective, and its feasibility is successfully verified by experiment.

Performance analysis of cross-seeding WDM-PON system using transfer matrix method

NASA Astrophysics Data System (ADS)

Simatupang, Joni Welman; Pukhrambam, Puspa Devi; Huang, Yen-Ru

2016-12-01

In this paper, a model based on the transfer matrix method is adopted to analyze the effects of Rayleigh backscattering and Fresnel multiple reflections on a cross-seeding WDM-PON system. As part of analytical approximation methods, this time-independent model is quite simple but very efficient when it is applied to various WDM-PON transmission systems, including the cross-seeding scheme. The cross seeding scheme is most beneficial for systems with low loop-back ONU gain or low reflection loss at the drop fiber for upstream data in bidirectional transmission. However for downstream data transmission, multiple reflections power could destroy the usefulness of the cross-seeding scheme when the reflectivity is high enough and the RN is positioned near OLT or close to ONU.

A chaotic modified-DFT encryption scheme for physical layer security and PAPR reduction in OFDM-PON

NASA Astrophysics Data System (ADS)

Fu, Xiaosong; Bi, Meihua; Zhou, Xuefang; Yang, Guowei; Li, Qiliang; Zhou, Zhao; Yang, Xuelin

2018-05-01

This letter proposes a modified discrete Fourier transform (DFT) encryption scheme with multi-dimensional chaos for the physical layer security and peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing passive optical network (OFDM-PON) system. This multiple-fold encryption algorithm is mainly composed by using the column vectors permutation and the random phase encryption in the standard DFT matrix, which can create ∼10551 key space. The transmission of ∼10 Gb/s encrypted OFDM signal is verified over 20-km standard single mode fiber (SMF). Moreover, experimental results show that, the proposed scheme can achieve ∼2.6-dB PAPR reduction and ∼1-dB improvement of receiver sensitivity if compared with the common OFDM-PON.

Paraoxonase-1 (PON1) rs662 Polymorphism and Its Association with Serum Lipid Levels and Longevity in the Bama Zhuang Population.

PubMed

Li, You; Liang, Guiyun; Shi, Liwei; Liang, Xue; Long, Bingshuang; Qin, Jian; Zhang, Zhiyong

2016-12-27

BACKGROUND The present study was performed to identify the association of PON1 rs662 polymorphism with serum lipid levels and human longevity in the Bama Zhuang population. MATERIAL AND METHODS PON1 genotypes were determined by Taqman SNP Genotyping Assays in 110 long-lived inhabitants (longevity group, aged 90-110 years), 110 healthy inhabitants in Bama County (control 1 group, aged 43-82 years) and 110 healthy inhabitants in Nandan County (control 2 group, aged 28-82 years) without family history of longevity. RESULTS BMI (body mass index) and TG (serum total triglyceride) level were lower in the longevity group than in the two control groups, while the contents of serum LDL-c (low-density lipoprotein cholesterol) and HDL-c (high-density lipoprotein cholesterol) and the levels of SBP (systolic blood pressure) and DBP (diastolic blood pressure) in the longevity group were higher than in the two control groups (p<0.01). Significant differences in the frequencies of three genotypes (GG, AG, and AA) were observed between the longevity group and control 2 group (χ²=15.190, p=0.001). The minor allele frequency (MAF) of rs662 was significantly higher in the longevity group than in the two control groups. The levels of HDL-c in the longevity group were different among the three genotypes (p<0.05). The levels of TG for GG and GG+AG genotypes were significantly different, while the levels of TC (total cholesterol) and HDL-c for AG and GG+AG genotypes were significantly different among the three groups (p<0.05). Serum lipid parameters were correlated with several environmental factors, including age, gender, DBP, SBP, and BMI. The association of PON1 rs662 polymorphism and serum lipid levels was different among the three groups. CONCLUSIONS PON1 polymorphism might be one of the genetic factors of longevity in the Bama Zhuang population. The PON1 rs662 SNP (single nucleotide polymorphism) was associated with serum HDL-c levels in the longevity group.

Serum Paraoxonase 1 Activity and Oxidative Stress in Pediatric Patients with Pulmonary Tuberculosis

PubMed Central

Torun, Emel; Gedik, Ahmet Hakan; Cakir, Erkan; Umutoglu, Tarik; Gok, Ozlem; Kilic, Ulkan

2014-01-01

Objectives The aim of this study was to determine the oxidative stress and paraoxonase 1 (PON1) levels in children with pulmonary tuberculosis (TB) compared to healthy controls, and to examine the association of demographical with oxidative stress. Subjects and Methods Forty children diagnosed with pulmonary TB and 40 age- and gender-matched healthy controls were enrolled in the study. Serum total antioxidant status (TAS), total oxidant status (TOS) and PON1 levels were measured. The oxidative stress index (OSI) was calculated to indicate the degree of oxidative stress. Results The TAS levels were lower (1.73 ± 0.5 vs. 2.54 ± 1.2 μmol Trolox Eq/l) while TOS levels were significantly higher (26.9 ± 14.4 vs. 13.4 ± 7.7 μmol H2O2 Eq/l) in the TB group than in the controls (p < 0.001). The OSI was significantly higher in the TB group than in the controls (21.2 ± 5.1 vs. 6.5 ± 4.9 units, p = 0.006). Serum PON1 levels were significantly lower in the TB group than in the controls (14.2 ± 13.2 vs. 28.4 ± 17.3 U/l, p < 0.001). The lower PON1 levels correlated with TAS and OSI levels but not with anthropometric parameters (r = 0.264, p = 0.018 and r = −0.255, p = 0.023, respectively). Conclusion The TOS and OSI levels were higher and the TAS and PON1 levels were lower in pediatric patients with pulmonary TB when compared to healthy controls. This indicates greater oxidative stress in the patients. PMID:25034194

Comparison of Pure Palm Olein Oil, Hydrogenated Oil-Containing Palm, and Canola on Serum Lipids and Lipid Oxidation Rate in Rats Fed with these Oils.

PubMed

Amini, Seyed-Asadollah; Ghatreh-Samani, Keihan; Habibi-Kohi, Arash; Jafari, Laleh

2017-02-01

Due to increased consumption of canola oil and hydrogenated oil containing palm and palm olein, and their possible effects on serum lipoproteins, the present study was conducted to determine the effects of these oils on lipids and lipid oxidation level. In this experimental study, 88 Wistar rats were randomly assigned to four groups. Control group (A) was on a normal diet. Groups B, C, and D, in addition to normal diet, were fed with hydrogenated oil-contained palm oil, pure palm olein oil, and canola oil, respectively for 4 weeks. Serum Biochemical factors [total cholesterol (TC), triglyceride (TG), LDL, HDL, LDL/HDL ratio, oxLDL, paraoxanase-1 (PON1), and malondialdehyde (MDA)] were measured. The lowest mean serum TC was seen in the control group and the highest in the group B. There were differences in TC, TG, HDL, MDA, and PON1 between the control group and other groups (P<0.001). The lowest and highest LDL/HDL ratios were observed in the group C and the control group, respectively. Significant differences were seen in OxLDL and PON1 between the control group and other three groups (P<0.05), while there were no significant differences in oxLDL and PON1 among the other three groups (P>0.05). MDA was higher in groups C and D. Canola oil, hydrogenated oil-containing palm and palm olein may increase atherosclerosis risk through decreasing PON1 activity and elevating oxLDL. Palm olein oils in rats' diets cause a considerable decrease in LDL and help to increase HDL.

A SIEPON based transmitter sleep mode energy-efficient mechanism in EPON

NASA Astrophysics Data System (ADS)

Nikoukar, AliAkbar; Hwang, I.-Shyan; Wang, Chien-Jung; Ab-Rahman, Mohammad Syuhaimi; Liem, Andrew Tanny

2015-06-01

The main energy consumption in computer networks is the access networks. The passive optical network (PON) has the least energy consumption among access network technologies. In addition, the time division multiplexing (TDM) Ethernet PON (EPON) is one of the best candidates to improve energy consumption by time utilization. The optical network unit (ONU) can utilize the time and save the energy in the EPON by turning off its transmitter/receiver when there is no upstream/downstream traffic. The ITU-T and IEEE organizations are published standards for energy-saving in the TDM-PON. Although their standards provide the framework to accomplish the energy-saving, the algorithms/criteria to generate events to accommodate various operational policies, time to wake up, parameter values for timers are out of scope of the standards. Many studies have proposed schemes for energy-saving in TDM-PON to achieve maximum energy saving. Even so, these schemes increase the mean packet delay and consequently, reduce the quality of service (QoS). In this paper, first we take a look to the state of the art for PON energy-saving. Additionally, a mechanism based on SIEPON standard in EPON with new components in the ONUs and optical line terminal (OLT) is proposed to save the transmitter energy and guarantee QoS. The proposed mechanism follows the SIEPON standard, considers the QoS first, and then saves the energy as far as possible. The ONU sleep controller unit (OSC) and green dynamic bandwidth allocation (GDBA) are used to calculate the ONU transmitter sleep (Tx) duration and grant the proper time to the ONUs. Simulation results show that the proposed energy-saving mechanism not only promises the QoS performance in terms of mean packet delay, packet loss, throughput, and jitter, but also saves energy in different maximum cycle times.

The influence of gemfibrozil on malondialdehyde level and paraoxonase 1 activity in wistar and fisher rats.

PubMed

Macan, Marija; Marija, Macan; Konjevoda, Paško; Paško, Konjevoda; Lovric, Jasna; Jasna, Lovrić; Koprivanac, Marijan; Marijan, Koprivanac; Kelava, Marta; Marta, Kelava; Vrkic, Nada; Nada, Vrkić; Bradamante, Vlasta; Vlasta, Bradamante

2011-06-01

There are diverse experimental data about the influence of gemfibrozil (GEM) on the production of hydrogen peroxide (H(2)O(2)) and antioxidant enzymes. We investigated the influence of GEM treatment on the production of malondialdehyde (MDA) level in tissues of normolipidaemic Wistar and Fisher rats which is an index of lipid peroxidation. Because serum paraoxonase 1 (PON1) is an important enzyme with specific protective function on metabolism of lipid peroxides, we examined the influence of GEM on PON1 activity in liver and serum. MDA level and enzyme activities were also determined 10 days after withdrawal of GEM treatment. The significantly increased levels of MDA in liver, kidney and heart of both rat strains were obtained after 3 weeks of GEM treatment. We propose two possibilities for the increase of MDA levels caused by GEM, induction of peroxisome proliferation and activities of enzymes that participated in occurrence of H(2)O(2) and possible reduction of enzyme activities including in H(2)O(2) metabolism. Ten days after withdrawal of GEM treatment, MDA levels in all tissue levels of both rat strains were less in comparison with GEM treatment. GEM caused a significant drop of PON1 activity in serum and liver of Fisher rats, and in liver of Wistar rats. We suggest that GEM, through induction of lipid peroxidation, caused the damage of hepatocytes with consequent reduction of PON1 synthesis. The increase in PON1 activity in serum and tissues of both rat strains 10 days after withdrawal of GEM treatment shows the fast recovery of enzyme synthesis. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

Cluster-based single-sink wireless sensor networks and passive optical network converged network incorporating sideband modulation schemes

NASA Astrophysics Data System (ADS)

Kumar, Love; Sharma, Vishal; Singh, Amarpal

2018-02-01

Wireless sensor networks have tremendous applications, such as civil, military, and environmental monitoring. In most of the applications, sensor data are required to be propagated over the internet/core networks, which result in backhaul setback. Subsequently, there is a necessity to backhaul the sensed information of such networks together with prolonging of the transmission link. Passive optical network (PON) is next-generation access technology emerging as a potential candidate for convergence of the sensed data to the core system. Earlier, the work with single-optical line terminal-PON was demonstrated and investigated merely analytically. This work is an attempt to demonstrate a practical model of a bidirectional single-sink wireless sensor network-PON converged network in which the collected data from cluster heads are transmitted over PON networks. Further, modeled converged structure has been investigated under the influence of double, single, and tandem sideband modulation schemes incorporating a corresponding phase-delay to the sensor data entities that have been overlooked in the past. The outcome illustrates the successful fusion of the sensor data entities over PON with acceptable bit error rate and signal to noise ratio serving as a potential development in the sphere of such converged networks. It has also been revealed that the data entities treated with tandem side band modulation scheme help in improving the performance of the converged structure. Additionally, analysis for uplink transmission reported with queue theory in terms of time cycle, average time delay, data packet generation, and bandwidth utilization. An analytical analysis of proposed converged network shows that average time delay for data packet transmission is less as compared with time cycle delay.

Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides.

PubMed

Singh, Satyender; Kumar, Vivek; Vashisht, Kapil; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

2011-11-15

Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p<0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37±2.15 vs. 6.24±1.37 tail% DNA, p<0.001). Further, the workers with CYP2D6*3PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p<0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of feeding grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of laying hens, turkey poults, and broiler breeder hens.

PubMed

Yegani, M; Chowdhury, S R; Oinas, N; MacDonald, E J; Smith, T K

2006-12-01

Three experiments were conducted to compare the effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of laying hens, turkey poults, and broiler breeder hens. In Experiment 1, thirty-six 45-wk-old laying hens were fed diets including the following for 4 wk: 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GMA). Concentrations of brain neurotransmitters and metabolites were analyzed in pons, hypothalamus, and cortex by HPLC with electrochemical detection. Neurotransmitters and the metabolites measured included dopamine, 3,4-dihydroxylphenyacetic acid, homovanillic acid, serotonin [5-hydroxytryptamine (5-HT)], 5-hydroxyindolacetic acid, epinephrine, and norepinephrine. The feeding of contaminated grains significantly increased concentrations of 5-HT and decreased the 5-hydroxyindolacetic acid:5-HT in the pons region in the brain stem. Dietary supplementation with GMA prevented these effects. There was no effect of diet on concentrations of other neurotransmitters or metabolites in the pons, hypothalamus, or cortex. In Experiment 2, thirty-six 1-d-old turkey poults were fed diets including the following for 4 wk: 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. Hypothalamic, pons, and cortex neurotransmitter concentrations were not affected by diet. In Experiment 3, forty-two 26-wk-old broiler breeder hens were fed diets including the following for 15 wk: 1) control, 2) contaminated grains, and 3) contaminated grains + 0.2% GMA. There was no effect of diet on neurotransmitter concentrations in the pons, hypothalamus, or cortex. It was concluded that differences in intraspecies effects of these mycotoxins on brain neurotransmitter concentrations might explain the intraspecies differences in the severity of Fusarium mycotoxin-induced reductions in feed intake.

Plane of nutrition during the preweaned period and Mannheimia haemolytica dose influence metabolic responses in post-weaned Holstein calves challenged with bovine herpesvirus-1 and Mannheimia haemolytica

USDA-ARS?s Scientific Manuscript database

To determine whether previous plane of milk replacer nutrition (PON) and M. haemolytica (MH) dose influences metabolic responses to a combined viral-bacterial respiratory challenge, Holstein calves (1 day of age; n=30) were assigned to treatments in a 2 x 3 factorial with preweaned PON and dose of M...

Plane of nutrition during the preweaned period and Mannheimia haemolytica dose influences inflammatory responses to a combined bovine herpesvirus-1 and Mannheimia haemolytica challenge in post-weaned Holstein calves

USDA-ARS?s Scientific Manuscript database

To determine whether previous plane of milk replacer nutrition (PON) and M. haemolytica (MH) dose influences inflammatory responses to a combined viral-bacterial respiratory challenge, Holstein calves (1 day of age; n=30) were assigned to treatments in a 2 x 3 factorial with preweaned PON and dose o...

In Silico Analyses of Substrate Interactions with Human Serum Paraoxonase 1

DTIC Science & Technology

2008-01-01

substrate interactions of HuPON1 remains elusive. In this study, we apply homology modeling, docking, and molecular dynamic (MD) simulations to probe the...mod- eling; docking; molecular dynamics simulations ; binding free energy decomposition. 486 PROTEINS Published 2008 WILEY-LISS, INC. yThis article is a...apply homology modeling, docking, and molecular dynamic (MD) simulations to probe the binding interactions of HuPON1 with representative substrates. The

Serum Oxidative Stress Levels in Patients with Nasal Septal Deviation

PubMed Central

Ekinci, Adnan; Karataş, Duran; Yetiş, Abdurrahman; Demir, Emre; Özcan, Müge

2017-01-01

Objective Comparison of the total oxidant status (TOS), total antioxidant status (TAS) and paraoxonase (PON1) serum levels in patients with nasal septum deviation (NSD) and healthy subjects. Methods The TAS, TOS, and PON1 serum levels of 47 patients with NSD (mean age 35.3) and 50 healthy subjects (mean age 37.8) were compared in this study. Results We found significantly higher TAS levels in the control group (p<0.001). The mean TAS value was 1.196 mmoL/L in the control group, whereas it was 1.046 mmoL/L in the NSD group. On the other hand, TOS was significantly higher in the NSD group (p<0.001). We found that the mean TOS value was 6.600 mmoL/L in the control group, and 20.194 mmoL/L in the NSD group. The NSD and control groups had similar PON1 levels (p=0.446). The mean PON1 value was 279.64 U/L in the control group, and 324.21 U/L in the NSD group. Conclusion We detected higher TOS and lower TAS levels in patients with NSD compared to healthy subjects. These results indicate that patients with NSD are exposed to oxidative stress. PMID:29392069

A CLS-based survivable and energy-saving WDM-PON architecture

NASA Astrophysics Data System (ADS)

Zhu, Min; Zhong, Wen-De; Zhang, Zhenrong; Luan, Feng

2013-11-01

We propose and demonstrate an improved survivable and energy-saving WDM-PON with colorless ONUs. It incorporates both energy-saving and self-healing operations. A simple effective energy-saving scheme is proposed by including an energy-saving control unit in the OLT and a control unit at each ONU. The energy-saving scheme realizes both dozing and sleep (offline) modes, which greatly improves the energy-saving efficiency for WDM-PONs. An intelligent protection switching scheme is designed in the OLT, which can distinguish if an ONU is in dozing/sleep (offline) state or a fiber is faulty. Moreover, by monitoring the optical power of each channel on both working and protection paths, the OLT can know the connection status of every fiber path, thus facilitating an effective protection switching and a faster failure recovery. The improved WDM-PON architecture not only significantly reduces energy consumption, but also performs self-healing operation in practical operation scenarios. The scheme feasibility is experimentally verified with 10 Gbit/s downstream and 1.25 Gbit/s upstream transmissions. We also examine the energy-saving efficiency of our proposed energy-saving scheme by simulation, which reveals that energy saving mainly arises from the dozing mode, not from the sleep mode when the ONU is in the online state.

Traffic-aware energy saving scheme with modularization supporting in TWDM-PON

NASA Astrophysics Data System (ADS)

Xiong, Yu; Sun, Peng; Liu, Chuanbo; Guan, Jianjun

2017-01-01

Time and wavelength division multiplexed passive optical network (TWDM-PON) is considered to be a primary solution for next-generation passive optical network stage 2 (NG-PON2). Due to the feature of multi-wavelength transmission of TWDM-PON, some of the transmitters/receivers at the optical line terminal (OLT) could be shut down to reduce the energy consumption. Therefore, a novel scheme called traffic-aware energy saving scheme with modularization supporting is proposed. Through establishing the modular energy consumption model of OLT, the wavelength transmitters/receivers at OLT could be switched on or shut down adaptively depending on sensing the status of network traffic load, thus the energy consumption of OLT will be effectively reduced. Furthermore, exploring the technology of optical network unit (ONU) modularization, each module of ONU could be switched to sleep or active mode independently in order to reduce the energy consumption of ONU. Simultaneously, the polling sequence of ONU could be changed dynamically via sensing the packet arrival time. In order to guarantee the delay performance of network traffic, the sub-cycle division strategy is designed to transmit the real-time traffic preferentially. Finally, simulation results verify that the proposed scheme is able to reduce the energy consumption of the network while maintaining the traffic delay performance.

Onion extract (Allium cepa L.), quercetin and catechin up-regulate paraoxonase 1 activity with concomitant protection against low-density lipoprotein oxidation in male Wistar rats subjected to oxidative stress.

PubMed

Jaiswal, Nidhi; Rizvi, Syed Ibrahim

2014-10-01

Paraoxonase 1 (PON1) protects the oxidative modification of low-density lipoprotein (LDL) and is a major anti-atherosclerotic protein component of high-density lipoprotein. We explored the effect of onion extract and flavonoids (quercetin and catechin) in the regulation of PON1 expression and correlating with oxidised LDL levels in male Wistar rats subjected to mercuric chloride (HgCl₂) induced oxidative insult. Rats were divided into eight groups: Control, Experimental (HgCl₂), Experimental + onion/catechin/quercetin, Positive control (Normal + onion/catechin/quercetin). Treatment continued for 4 weeks. PON1 activity and radical scavenging activity decreased in the Experimental group (P < 0.001) with increased susceptibility of LDL for oxidation and plasma malondialdehyde levels (P < 0.001). Onion extract significantly attenuated the adverse effects of HgCl₂ by up-regulating PON1 activity (P < 0.05), radical scavenging activity (P < 0.01), and protected against LDL oxidation (P < 0.001) and lipid peroxidation (P < 0.01). Similar effects were observed with quercetin and to a lesser extent with catechin. The findings may explain the anti-atherosclerotic effect of onion and also foods containing quercetin and catechins.

Association between Q192R paraoxonase 1 polymorphism and serumadipocyte-fatty acid binding protein (FABP4) levels in Mexican women.

PubMed

Ochoa-Martínez, Ángeles C; Ruíz-Vera, Tania; Orta-García, Sandra T; Domínguez-Cortinas, Gabriela; Jiménez-Avalos, Jorge A; Pérez-Maldonado, Iván N

2017-06-01

This study aimed to evaluate the genetic effects of PON1 Q192R polymorphism on serum FABP4 levels in Mexican women. PON1 Q192R polymorphism was genotyped using a TaqMan allelic discrimination assay and serum FABP4 concentration was measured using an enzyme-linked immunosorbent assay. The distribution of genotype frequencies in the assessed women (PON1 Q192R polymorphism) was QQ = 20%, QR = 48% and RR = 32%. Significantly higher serum FABP4 levels were found in women with genotype QR/RR (20.6 ± 2.20 ng/mL), when compared with the levels found in the QQ group (12.8 ± 1.70 ng/mL) (p = .004). After, the odds ratio (OR) was calculated by binomial logistic regression analysis and a significantly higher OR was found in the QR/RR group when compared with the QQ group (OR = 3.45; 95% CI = 1.80-16.50; p < .05). The results support an association between 192R-allele of the PON1 polymorphism (Q192R) and increased serum FABP4 levels (suggested as an early biomarker of CVDs risk) in assessed Mexican women.

Protective Effects of Caffeic Acid Phenethyl Ester on Fluoxetine-Induced Hepatotoxicity: An Experimental Study.

PubMed

Yılmaz, Ahmet; Elbey, Bilal; Yazgan, Ümit Can; Dönder, Ahmet; Arslan, Necmi; Arslan, Serkan; Alabalık, Ulaş; Aslanhan, Hamza

2016-01-01

Background. The aim of the study was to analyse the effect of caffeic acid phenethyl ester (CAPE) on fluoxetine-induced hepatotoxicity in rats. Materials and Methods. Group I served as control. Group II received CAPE intraperitoneally. Group III received fluoxetine per orally. Group IV received fluoxetine and CAPE. The total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), and liver enzymes including paraoxonase-1 (PON-1), aspartate transaminase, and alanine transaminase levels were measured. Liver tissues were processed histopathologically for evaluation of liver injury and to validate the serum enzyme levels. Results. An increase in TOS and OSI and a decrease in TAC and PON-1 levels in serum and liver tissues of Group III were observed compared to Groups I and II. After treatment with CAPE, the level of TOS and OSI decreased while TAC and PON-1 increased in serum and liver in Group IV. Histopathological examination of the liver revealed hepatic injury after fluoxetine treatment and reduction of injury with CAPE treatment. Conclusion. Our results suggested that CAPE treatment provided protection against fluoxetine toxicity. Following CAPE treatment with fluoxetine-induced hepatotoxicity, TOS and OSI levels decreased, whereas PON-1 and TAC increased in the serum and liver.

Towards Understanding the Catalytic Mechanism of Human Paraoxonase 1: Experimental and In Silico Mutagenesis Studies.

PubMed

Tripathy, Rajan K; Aggarwal, Geetika; Bajaj, Priyanka; Kathuria, Deepika; Bharatam, Prasad V; Pande, Abhay H

2017-08-01

Human paraoxonase 1 (h-PON1) is a ~45-kDa serum enzyme that can hydrolyze a variety of substrates, including organophosphate (OP) compounds. It is a potential candidate for the development of antidote against OP poisoning in humans. However, insufficient OP-hydrolyzing activity of native enzyme affirms the urgent need to develop improved variant(s) having enhanced OP-hydrolyzing activity. The crystal structure of h-PON1 remains unsolved, and the molecular details of how the enzyme catalyses hydrolysis of different types of substrates are also not clear. Understanding the molecular details of the catalytic mechanism of h-PON1 is essential to engineer better variant(s) of enzyme. In this study, we have used a random mutagenesis approach to increase the OP-hydrolyzing activity of recombinant h-PON1. The mutants not only showed a 10-340-fold increased OP-hydrolyzing activity against different OP substrates but also exhibited differential lactonase and arylesterase activities. In order to investigate the mechanistic details of the effect of observed mutations on the hydrolytic activities of enzyme, molecular docking studies were performed with selected mutants. The results suggested that the observed mutations permit differential binding of substrate/inhibitor into the enzyme's active site. This may explain differential hydrolytic activities of the enzyme towards different substrates.

High-Speed Burst-Mode Clock and Data Recovery Circuits for Multiaccess Networks

NASA Astrophysics Data System (ADS)

Shastri, Bhavin J.

Optical multiaccess networks, and specifically passive optical networks (PONs) are considered to be the most promising technologies for the deployment of fiber-to-the-premises/home/user (FTTx) to solve the problem of limited bandwidth in local area networks with a low-cost solution and a guaranteed quality of service. In a PON, multiple users share the fiber infrastructure in a point-to-multipoint (P2MP) network. This topology introduce optical path delays which inherently cause the data packets to undergo amplitude variations up to 20 dB and phase variations from --2pi to +2pi rad--burst-mode traffic. Consequently, this creates new challenges for the design and test of optical receivers front-ends and clock and data recovery circuits (CDRs), in particular, burst-mode CDRs (BM-CDRs). The research presented in this thesis investigates BM-CDRs, both theoretically and experimentally. We demonstrate two novel BM-CDR architectures. These BM-CDRs achieve error-free operation [bit error rate (BER) <10e--10] while providing instantaneous (0 preamble bit) clock phase acquisition for any phase step (+/-2pi rad) between successive bursts. Instantaneous phase acquisition improves the physical efficiency of upstream PON traffic, and increases the effective throughput of the system by raising the information rate. Our eloquent, scalable BM-CDR architectures leverage the design of low complexity commercial electronics providing a cost-effective solution for PONs. The first BM-CDR (rated at 5 Gb/s) is based on phase-tracking time domain oversampling (semiblind) CDR operated at 2x the bit rate and a clock phase aligner (CPA) that makes use of a phase picking algorithm. The second BM-CDR (rate at 10 Gb/s) is based on semiblind space domain oversampling and employs a phase-tracking CDR with multiphase clocks at the bit rate and a CPA with a novel phase picking algorithm. We experimentally demonstrate these BM-CDRs in optical test beds and study the effect of channel-impairments in: (1) 5 Gb/s time-division multiplexing gigabit PON 20-km uplink; (2) 2.5 Gb/s overlapped subcarrier-multiplexing wavelength-division multiplexed PON 20-km uplink; (3) 1.25 Gb/s 1300-km deployed fiber link spanning Montreal--Quebec City and back; and (4) 622 Mb/s in a 7-user spectral amplitude-coded optical code-division multiple access 20-km PON uplink. We also provide a theoretical framework to model and analyze BM-CDRs. We develop a unified probabilistic theory of BM-CDRs based on semiblind oversampling techniques in either the time or space domain. This theory has also been generalized for conventional CDRs and Nx-oversampling CDRs. Based on this theory, we perform a comprehensive theoretical analysis to quantify the performance of the proposed BM-CDRs in terms of the BER and packet loss ratio to assess the tradeoffs between various parameters, and compare the results experimentally to validate the theoretical model. This analysis coupled with the experimental results will refine theoretical models PONs, and provide input for establishing realistic power budgets.

A Novel Reliable WDM-PON System

NASA Astrophysics Data System (ADS)

Chen, Benyang; Gan, Chaoqin; Qi, Yongqian; Xia, Lei

2011-12-01

In this paper, a reliable Wavelength-Division-Multiplexing Passive Optical Network (WDM-PON) system is proposed. It can provide the protection against both the feeder fiber failure and the distribution fiber failure. When the fiber failure occurs, the corresponding switches in the OLT and in the ONU can switch to the protection link without affecting the users in normal status. That is to say, the protection for one ONU is independent of the other ONUs.

Photonic integrated transmitter and receiver for NG-PON2

NASA Astrophysics Data System (ADS)

Tavares, Ana; Lopes, Ana; Rodrigues, Cláudio; Mãocheia, Paulo; Mendes, Tiago; Brandão, Simão.; Rodrigues, Francisco; Ferreira, Ricardo; Teixeira, António

2014-08-01

In this paper the authors present a monolithic Photonic Integrated Circuit which includes a transmitter and a receiver for NG-PON2. With this layout it is possible to build an OLT and, by redesigning some filters, also an ONU. This technology allows reducing the losses in the transmitter and in the receiver, increasing power budget, and also reducing the OEO conversions, which has been a major problem that operators want to surpass.

Energy-efficient orthogonal frequency division multiplexing-based passive optical network based on adaptive sleep-mode control and dynamic bandwidth allocation

NASA Astrophysics Data System (ADS)

Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun

2016-02-01

We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.

Atomic Layer Deposition of the Solid Electrolyte LiPON

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozen, Alexander C.; Pearse, Alexander J.; Lin, Chuan -Fu

We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phosphorousoxynitride (LiPON) using lithium tert-butoxide (LiO tBu), H 2O, trimethylphosphate (TMP), and plasma N 2 ( PN 2) as precursors. We use in-situ spectroscopic ellipsometry to determine growth rates for process optimization to design a rational, quaternary precursor ALD process where only certain substrate–precursor chemical reactions are favorable. We demonstrate via in-situ XPS tunable nitrogen incorporation into the films by variation of the PN 2 dose and find that ALD films over approximately 4.5% nitrogen are amorphous, whereas LiPON ALD films with less than 4.5% nitrogen aremore » polycrystalline. Lastly, we characterize the ionic conductivity of the ALD films as a function of nitrogen content and demonstrate their functionality on a model battery electrode—a Si anode on a Cu current collector.« less

Study on the capability of four-level partial response equalization in RSOA-based WDM-PON

NASA Astrophysics Data System (ADS)

Guo, Qi; Tran, An Vu

2010-12-01

The expected development of advanced video services with HDTV quality demands the delivery of more than Gb/s link to end users across the last mile connection. Future access networks are also required to have long reach for reduction in the number of central offices (CO). Fueled by those requirements, we propose a novel equalization scheme that increases the capacity and reach of the wavelength division multiplexing passive optical network (WDM-PON) based on a low bandwidth reflective semiconductor optical amplifier (RSOA). We investigate the characteristics of 10 Gb/s upstream transmission in WDM-PON using RSOA with only 1.2 GHz electrical bandwidth and various lengths of fiber. It is proven that the proposed four-level partial response equalizer (PRE) is capable of mitigating the impact of ISI in the received signals from optical network units (ONU) located 0 km to 75 km away from the optical line terminal (OLT).

The significance of the measurement of serum xanthine oxidase and oxidation markers in patients with acute organophosphorus pesticide poisoning.

PubMed

Zhang, J-W; Lv, G-C; Zhao, Y

2010-01-01

This study investigated whether xanthine oxidase (XO) plays an important role in the mechanism of toxicity of acute organophosphorus pesticide poisoning (AOPP). The serum activities of XO, superoxide dismutase (SOD), paraoxonase-1 (PON1), butyrylcholinesterase (BChE) and malondialdehyde (MDA) were compared in 49 patients with AOPP and 50 age- and gender-matched healthy controls. Serum XO and MDA activities were higher and the serum SOD, PON1 and BChE activities were lower in the AOPP patients compared with the controls. Pearson correlation analysis demonstrated a significant negative correlation between XO activity and the SOD, PON1 and BChE activities, but a significant positive correlation between XO activity and MDA. These results suggest that increased activity of XO and decreased antioxidant enzyme activity contribute to the development of oxidative injury in AOPP patients. Thus, effective antioxidant therapy may be a therapeutic option following AOPP.

Experimental demonstration of time- and mode-division multiplexed passive optical network

NASA Astrophysics Data System (ADS)

Ren, Fang; Li, Juhao; Tang, Ruizhi; Hu, Tao; Yu, Jinyi; Mo, Qi; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

2017-07-01

A time- and mode-division multiplexed passive optical network (TMDM-PON) architecture is proposed, in which each optical network unit (ONU) communicates with the optical line terminal (OLT) independently utilizing both different time slots and switched optical linearly polarized (LP) spatial modes. Combination of a mode multiplexer/demultiplexer (MUX/DEUX) and a simple N × 1 optical switch is employed to select the specific LP mode in each ONU. A mode-insensitive power splitter is used for signal broadcast/combination between OLT and ONUs. We theoretically propose a dynamic mode and time slot assignment scheme for TMDM-PON based on inter-ONU priority rating, in which the time delay and packet loss ratio's variation tendency are investigated by simulation. Moreover, we experimentally demonstrate 2-mode TMDM-PON transmission over 10 km FMF with 10-Gb/s on-off keying (OOK) signal and direct detection.

Adaptive upstream optical power adjustment depending on required power budget in PON access

NASA Astrophysics Data System (ADS)

Yeh, C. H.; Chow, C. W.; Liu, Y. L.

2012-11-01

According to the present passive optical network (PON) standard, the fiber transmission lengths are from 500 m to 20 km between the optical line terminal (OLT) and different optical network units (ONUs). It will result in difference power losses (ΔPloss) from 4 to 5 dB. Hence, we propose to adjust adaptively the output optical power of the upstream laser diode (LD) depending on the different fiber lengths. With the different fiber transmission lengths, we can properly adjust the bias current and modulation index of upstream LD for energy-saving. We characterize and analyze experimentally the relationship of output optical power and modulation amplitude Vamp under different fiber transmissions in PON access. Moreover, due to the adaptive power control of upstream signal, the optical upstream equalization also can be retrieved with power variation of 1.1 dB in this experiment.

A WDM-PON with DPSK modulated downstream and OOK modulated upstream signals based on symmetric 10 Gbit/s wavelength reused bidirectional reflective SOA

NASA Astrophysics Data System (ADS)

El-Nahal, Fady I.

2017-01-01

We investigate a wavelength-division-multiplexing passive optical network (WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying (DPSK) downstream signals and on-off keying (OOK) upstream signals, respectively. A wavelength reused scheme is employed to carry the upstream data by using a reflective semiconductor optical amplifier (RSOA) as an intensity modulator at the optical network unit (ONU). The constant-intensity property of the DPSK modulation format can keep high extinction ratio ( ER) of downstream signal and reduce the crosstalk to the upstream signal. The bit error rate ( BER) performance of our scheme shows that the proposed 10 Gbit/s symmetric WDM-PON can achieve error free transmission over 25-km-long fiber transmission with low power penalty.

Atomic Layer Deposition of the Solid Electrolyte LiPON

DOE PAGES

Kozen, Alexander C.; Pearse, Alexander J.; Lin, Chuan -Fu; ...

2015-07-09

We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phosphorousoxynitride (LiPON) using lithium tert-butoxide (LiO tBu), H 2O, trimethylphosphate (TMP), and plasma N 2 ( PN 2) as precursors. We use in-situ spectroscopic ellipsometry to determine growth rates for process optimization to design a rational, quaternary precursor ALD process where only certain substrate–precursor chemical reactions are favorable. We demonstrate via in-situ XPS tunable nitrogen incorporation into the films by variation of the PN 2 dose and find that ALD films over approximately 4.5% nitrogen are amorphous, whereas LiPON ALD films with less than 4.5% nitrogen aremore » polycrystalline. Lastly, we characterize the ionic conductivity of the ALD films as a function of nitrogen content and demonstrate their functionality on a model battery electrode—a Si anode on a Cu current collector.« less

Paraoxonase Activity and Oxidative Status in Patients with Tinnitus

PubMed Central

Akyüz, Servet; Somuk, Battal Tahsin; Soyalic, Harun; Yılmaz, Beyhan; Taskin, Abdullah; Bilinc, Hasan; Aksoy, Nurten

2016-01-01

Background and Objectives The aim of this study was to investigate serum paraoxanase-1 (PON) activity, total oxidant status (TOS), total antioxidant status (TAS), and the oxidative stress index (OSI) in tinnitus; and to compare the results with data from healthy subjects. Subjects and Methods A total of 114 subjects-54 patients with tinnitus and 60 healthy controls were enrolled in this study. Serum PON activity, TOS, TAS, and OSI levels were measured. Results In the tinnitus group, TAS, and PON were significantly lower than in the control group (p<0.001). However, the TOS, and OSI levels were significantly higher in the tinnitus group than in the control group (p<0.001). Conclusions According to the data obtained from the present study, patients with tinnitus were exposed to potent oxidative stress. Oxidative stress may be the key contributing factor to the pathogenesis of tinnitus. PMID:27144229

Grant management procedure for energy saving TDM-PONs

NASA Astrophysics Data System (ADS)

Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; AL-Hazemi, Fawaz; Choi, Jun Kyun

2018-01-01

In order to minimize energy consumption in Time Division Multiplexing-Passive Optical Network (TDM-PON), IEEE and ITU-T have mandated sleep mode mechanism for Optical Network Units (ONUs) in the latest TDM-PON standards (e.g. IEEE P1904.1 SIEPON, ITU-T G.sup45). The sleep mode mechanism is a promising mean for maximizing energy saving in an ONU. An ONU in sleep mode flips between sleep and active state depending on the presence or absent of upstream and downstream frames. To ensure Quality of Service (QoS) of upstream frames, the recent TDM-PON standards introduced an early wake-up mechanism, in which an ONU is forced to leave the sleep state on upstream frame arrival. When the Optical Line Terminal (OLT) of a TDM-PON allows early wake-up of its connected ONUs, it allocates gratuitous grants for the sleeping ONUs along with allocating upstream grants for the ONUs in active state. Note that, the gratuitous grants control message sent periodically by the OLT on Inter-Gratuitous grant Interval (IGI) time. After leaving sleep state due to the arrival of upstream frame, the ONU uses its allocated gratuitous grant to send a control message mentioning the amount of upstream bandwidth (upstream grant) required in order to forward the remaining frames in its buffer. However, the existing early wake-up process of ONU can lead to increase the energy consumption of an ONU. It is because of the ONU wakes-up immediately from the sleep state on arrival of the upstream frame, but even so, it needs to wait for forwarding the frame until its allocated gratuitous grant period, resulting in spending energy unnecessarily. In addition, current energy saving solution for TDM-PONs do not provide a clear solution on how to manage different types of grants (e.g. listening grant, upstream transmission grant) within a Dynamic Bandwidth Allocation (DBA) polling cycle. To address this problem, we propose a state-of-art Grant Management Procedure (GMP) in order to maximize energy saving in a TDM-PON with sleep mode enabled ONUs. GMP contributes in defining the location of the different types of grants during a DBA polling cycle. Furthermore, GMP devises a mechanism so as to allow an ONU to predict its assigned gratuitous grant control message arrival time, thereby allowing an ONU to remain its transceiver unit powered off until the arrival period of the next gratuitous grant control message, increasing the energy saving of the ONU. Results show that, with the increment of IGI, the energy saving performance of an ONU with GMP increases noticeably in compare to a conventional ONU (an ONU that does not use GMP) without imposing any additional upstream frame delay.

Gadolinium Brain Deposition after Macrocyclic Gadolinium Administration: A Pediatric Case-Control Study.

PubMed

Tibussek, Daniel; Rademacher, Christin; Caspers, Julian; Turowski, Bernd; Schaper, Jörg; Antoch, Gerald; Klee, Dirk

2017-10-01

Purpose To determine whether signal intensity (SI) in T1 sequences as a potential indicator of gadolinium deposition increases after repeated administration of the macrocyclic gadolinium-based contrast agents (GBCAs) gadoteridol and gadoterate meglumine in a pediatric cohort. Materials and Methods This retrospective case-control study of children with brain tumors who underwent nine or more contrast material-enhanced brain magnetic resonance (MR) imaging studies from 2008 to 2015 was approved by the local ethics board. Informed consent was obtained for MR imaging. Twenty-four case patients aged 5-18 years and appropriate control patients with nonpathologic MR neuroimaging findings (and no GBCA administration), matched for age and sex, were inculded. SI was measured on unenhanced T1-weighted MR images for the following five regions of interest (ROIs): the dentate nucleus (DN), pons, substantia nigra (SN), pulvinar thalami, and globus pallidus (GP). Paired t tests were used to compare SI and SI ratios (DN to pons, GP to thalamus) between case patients and control patients. Pearson correlations between relative signal changes and the number of GBCA administrations and total GBCA dose were calculated. Results The mean number of GBCA administrations was 14.2. No significant differences in mean SI for any ROI and no group differences were found when DN-to-pons and GP-to-pulvinar ratios were compared (DN-to-pons ratio in case patients: mean, 1.0083 ± 0.0373 [standard deviation]; DN-to-pons ratio in control patients: mean, 1.0183 ± 0.01917; P = .37; GP-to-pulvinar ratio in case patients: mean, 1.1335 ± 0.04528; and GP-to-pulvinar ratio in control patients: mean, 1.1141 ± 0.07058; P = .29). No correlation was found between the number of GBCA administrations or the total amount of GBCA administered and signal change for any ROI. (Number of GBCA applications: DN: r = -0.254, P = .31; pons: r = -0.097, P = .65; SN: r = -0.194, P = .38; GP: r = -0.175, P = .41; pulvinar: r = -0.067, P = .75; total amount of administered GBCA: DN: r = 0.091, P = .72; pons: r = 0.106, P = .62; SN: r = -0.165, P = .45; GP: r = 0.111, P = .61; pulvinar: r = 0.173, P = .42.) Conclusion Multiple intravenous administrations of these macrocyclic GBCAs in children were not associated with a measurable increase in SI in T1 sequences as an indicator of brain gadolinium deposition detectable by using MR imaging. Additional imaging and pathologic studies are needed to confirm these findings. © RSNA, 2017 Online supplemental material is available for this article.

Sources and transformation of dissolved and particulate organic nitrogen in the North Pacific Subtropical Gyre indicated by compound-specific δ15N analysis of amino acids

NASA Astrophysics Data System (ADS)

Yamaguchi, Yasuhiko T.; McCarthy, Matthew D.

2018-01-01

This study explores the use of compound-specific nitrogen isotopes of amino acids (δ15NAA) of coupled dissolved and particulate organic nitrogen (DON, PON) samples as a new approach to examine relative sources, transformation processes, and the potential coupling of these two major forms of N cycle in the ocean water column. We measured δ15NAA distributions in high-molecular-weight dissolved organic nitrogen (HMW DON) and suspended PON in the North Pacific Subtropical Gyre (NPSG) from surface to mesopelagic depths. A new analytical approach achieved far greater δ15NAA measurement precision for DON than earlier work, allowing us to resolve previously obscured differences in δ15NAA signatures, both with depth and between ON pools. We propose that δ15N values of total hydrolysable amino acids (THAA) represents a proxy for proteinaceous ON δ15N values in DON and PON. Together with bulk δ15N values, this allows δ15N values and changes in bulk, proteinaceous, and ;other-N; to be directly evaluated. These novel measurements suggest three main conclusions. First, the δ15NAA signatures of both surface and mesopelagic HMW DON suggest mainly heterotrophic bacterial sources, with mesopelagic HMW DON bearing signatures of far more degraded material compared to surface material. These results contrast with a previous proposal that HMW DON δ15NAA patterns are essentially ;pre-formed; by cyanobacteria in the surface ocean, undergo little change with depth. Second, different δ15NAA values and patterns of HMW DON vs. suspended PON in the surface NPSG suggest that sources and cycling of these two N reservoirs are surpisingly decoupled. Based on molecular δ15N signatures, we propose a new hypothesis that production of surface HMW DON is ultimately derived from subsurface nitrate, while PON in the mixed layer is strongly linked to N2 fixation and N recycling. In contrast, the comparative δ15NAA signatures of HMW DON vs. suspended PON in the mesopelagic also suggest a possible PON source for some HMW DON in the mid-water column. Together, these results suggest that conversion of relatively labile ON to less labile DON by heterotrophic bacteria (a ;microbial nitrogen pump;) may be the key pathway for production and alteration of DON in both the surface and the mesopelagic oligotrophic ocean. Finally, in contrast to THAA, δ15N values of the other-N were substantially less affected by heterotrophic alteration, which may be consistent with a larger than expected contribution of amino sugars, or other less labile nitrogenous organic molecules.

Flux and stable C and N isotope composition of sinking particles in the Ulleung Basin of the East/Japan Sea

NASA Astrophysics Data System (ADS)

Hyun Kwak, Jung; Han, Eunah; Hwang, Jeomshik; Kim, Young, II; Lee, Chung Il; Kang, Chang-Keun

2017-09-01

Seasonal variability of sinking fluxes of total mass (TMF), particulate organic carbon and nitrogen (POC and PON) was examined using sinking particles collected from sediment traps during July 2011 to December 2011, and December 2012 to June 2013 at an offshore channel site; and from November 2013 to August 2014 at a nearshore slope site of the Ulleung Basin in the East/Japan Sea. δ13C and δ15N values of sinking particles were measured to elucidate the major export processes of POC and PON. Annual TMF (112-638 g m-2 yr-1) and fluxes of POC and PON (9.6-32.1 g C m-2 yr-1 and 1.2-4.5 g N m-2 yr-1, respectively) in the Ulleung Basin corresponded to the upper limit of values reported for other open seas and oceans in the world. No great seasonal variability in both quantitative (TMF, and fluxes and contents of POC and PON) and qualitative (C/N ratios, and δ13C and δ15N values) estimates of vertical fluxes was observed, reflecting a steady standing stock of chlorophyll a in the upper part of water column. Furthermore, high contents of POC and PON and nearly constant δ13C and δ15N values in sinking particles collected in the sediment traps, indicate that primary production in the euphotic zone may be a good predictor of TMF and export flux of organic matter. In this regard, our pilot study points out the importance of high annual primary production and low water temperature (<1 °C) beneath the 200-m water depth, which would enable more sinking particles to be preserved during export process by limiting microbial decomposition activity in the water column, in determining the high annual flux of sinking particles in the Ulleung Basin (UB). A simple stable isotope mixing model of sinking particles indicates that despite a slight seasonal variation, the contribution of intact phytoplankton to sinking organic flux is significant to the POC and PON flux in the UB. Further continuous time series sediment trap experiments are proposed to estimate the contribution of allochthonus sources such as lateral advection through resuspended clay mineral, and aeolian and terrestrial inputs to the sedimentary flux.

Examination of plasma PON1 paraoxonase activity and genotype in Gulf War veterans

DTIC Science & Technology

2017-10-01

cholinergic” effects (e.g., personal pesticide use, exposure to OP nerve agents) in subgroups of veterans with different PON1192 genotype. (2...associations between GWI and GW-related exposures with the potential for “cholinergic” effects (e.g., personal pesticide use, exposure to OP nerve agents) in...learning and careers in science, technology, and the humanities . What do you plan to do during the next reporting period to accomplish the goals

DWDM-PON at 25 GHz channel spacing based on ASE injection seeding.

PubMed

Kim, Joon-Young; Moon, Sang-Rok; Yoo, Sang-Hwa; Lee, Chang-Hee

2012-12-10

We demonstrate a 25 GHz-channel-spaced DWDM-PON based on ASE injection seeding. A 60 km transmission at 1.25 Gb/s per channel is available with a 2nd generation FEC. The major limiting factor is the optical back reflection induced penalty. Thus a high gain reflective modulator and/or relocation of the seed light increase the transmission length. We demonstrated 90 km transmission with relocated seed light to remote node.

A novel PON-based mobile distributed cluster of antennas approach to provide impartial and broadband services to end users

NASA Astrophysics Data System (ADS)

Sana, Ajaz; Saddawi, Samir; Moghaddassi, Jalil; Hussain, Shahab; Zaidi, Syed R.

2010-01-01

In this research paper we propose a novel Passive Optical Network (PON) based Mobile Worldwide Interoperability for Microwave Access (WiMAX) access network architecture to provide high capacity and performance multimedia services to mobile WiMAX users. Passive Optical Networks (PON) networks do not require powered equipment; hence they cost lower and need less network management. WiMAX technology emerges as a viable candidate for the last mile solution. In the conventional WiMAX access networks, the base stations and Multiple Input Multiple Output (MIMO) antennas are connected by point to point lines. Ideally in theory, the Maximum WiMAX bandwidth is assumed to be 70 Mbit/s over 31 miles. In reality, WiMAX can only provide one or the other as when operating over maximum range, bit error rate increases and therefore it is required to use lower bit rate. Lowering the range allows a device to operate at higher bit rates. Our focus in this research paper is to increase both range and bit rate by utilizing distributed cluster of MIMO antennas connected to WiMAX base stations with PON based topologies. A novel quality of service (QoS) algorithm is also proposed to provide admission control and scheduling to serve classified traffic. The proposed architecture presents flexible and scalable system design with different performance requirements and complexity.

A high performance long-reach passive optical network with a novel excess bandwidth distribution scheme

NASA Astrophysics Data System (ADS)

Chao, I.-Fen; Zhang, Tsung-Min

2015-06-01

Long-reach passive optical networks (LR-PONs) have been considered to be promising solutions for future access networks. In this paper, we propose a distributed medium access control (MAC) scheme over an advantageous LR-PON network architecture that reroutes the control information from and back to all ONUs through an (N + 1) × (N + 1) star coupler (SC) deployed near the ONUs, thereby overwhelming the extremely long propagation delay problem in LR-PONs. In the network, the control slot is designed to contain all bandwidth requirements of all ONUs and is in-band time-division-multiplexed with a number of data slots within a cycle. In the proposed MAC scheme, a novel profit-weight-based dynamic bandwidth allocation (P-DBA) scheme is presented. The algorithm is designed to efficiently and fairly distribute the amount of excess bandwidth based on a profit value derived from the excess bandwidth usage of each ONU, which resolves the problems of previously reported DBA schemes that are either unfair or inefficient. The simulation results show that the proposed decentralized algorithms exhibit a nearly three-order-of-magnitude improvement in delay performance compared to the centralized algorithms over LR-PONs. Moreover, the newly proposed P-DBA scheme guarantees low delay performance and fairness even when under attack by the malevolent ONU irrespective of traffic loads and burstiness.

Optical frequency comb generation with high tone-to-noise ratio for large-capacity wavelength division multiplexed passive optical network

NASA Astrophysics Data System (ADS)

Ullah, Rahat; Liu, Bo; Zhang, Qi; Tian, Qinghua; Tian, Feng; Qu, Zhaowei; Yan, Cheng; Khan, Muhammad Saad; Ahmad, Ibrar; Xin, Xiangjun

2015-11-01

We propose a technique for the generation of optical frequency comb from a single source, which reduces the costs of optical access networks. Two Mach-Zehnder modulators are cascaded with one phase modulator driven by radiofrequency signals. With 10-GHz frequency spacing, the generated 40 optical multicarriers have good tone-to-noise ratio with least excursions in their comb lines. The laser array at the optical line terminal of the conventional wavelength division multiplexed passive optical network (WDM-PON) system has been replaced with optical frequency comb generator (OFCG), which may result in cost-effective optical line terminal (OLT) supporting a large-capacity WDM-PON system. Of 40 carriers generated, each carrier carries 10 Gbps data based on differential phase-shift keying. Four hundred Gbps multiplexed data from all channels are successfully transmitted through a fiber span of 25 km with negligible power penalties. Part of the downlink signal is used in uplink transmission at optical network unit where intensity-modulated on-off keying is deployed for remodulation. Theoretical analysis of the proposed WDM-PON system based on OFCG are in good agreement with simulation results. The metrics considered for the analysis of the proposed OFCG in a WDM-PON system are power penalties of the full-duplex transmission, eye diagrams, and bit error rate.

OTACT: ONU Turning with Adaptive Cycle Times in Long-Reach PONs

NASA Astrophysics Data System (ADS)

Zare, Sajjad; Ghaffarpour Rahbar, Akbar

2015-01-01

With the expansion of PON networks as Long-Reach PON (LR-PON) networks, the problem of degrading the efficiency of centralized bandwidth allocation algorithms threatens this network due to high propagation delay. This is because these algorithms are based on bandwidth negotiation messages frequently exchanged between the optical line terminal (OLT) in the Central Office and optical network units (ONUs) near the users, which become seriously delayed when the network is extended. To solve this problem, some decentralized algorithms are proposed based on bandwidth negotiation messages frequently exchanged between the Remote Node (RN)/Local Exchange (LX) and ONUs near the users. The network has a relatively high delay since there are relatively large distances between RN/LX and ONUs, and therefore, control messages should travel twice between ONUs and RN/LX in order to go from one ONU to another ONU. In this paper, we propose a novel framework, called ONU Turning with Adaptive Cycle Times (OTACT), that uses Power Line Communication (PLC) to connect two adjacent ONUs. Since there is a large population density in urban areas, ONUs are closer to each other. Thus, the efficiency of the proposed method is high. We investigate the performance of the proposed scheme in contrast with other decentralized schemes under the worst case conditions. Simulation results show that the average upstream packet delay can be decreased under the proposed scheme.

Association of Paraoxonase-1 Q192R (rs662) Single Nucleotide Variation with Cardiovascular Risk in Coffee Harvesters of Central Colombia

PubMed Central

Garzón-Castaño, Sandra; Ramos-Márquez, Martha E.; Hernández-Cañaveral, Iván

2017-01-01

Paraoxonase 1 (PON1), a high-density lipoprotein-associated antioxidant enzyme, hydrolyzes several organophosphate pesticides and oxidized lipids. The PON1 Q192R polymorphism affects the catalytic efficiency and is considered a risk factor for pesticide intoxication and cardiovascular disease (CVD) but the association is not consistent between individuals or populations. We aimed to study the association of PON1 Q192R polymorphism with CVD risk in coffee harvesters of central Colombia. Demographics were collected from 205 subjects via standardized questionnaires. Lipid profiles and serum butyrylcholinesterase (BChE) were measured by standard procedures. The calculated 10-year atherosclerotic CVD (ASCVD) risk was used as the cardiovascular risk estimate. Q192R genotype was determined by real-time PCR. Prevalence of hypertension, hypercholesterolemia, and the 10-year ASCVD risk was 33%, 62%, and 22%, respectively. BChE levels were no indicative of recent pesticide exposure, although a positive correlation was observed with BChE and hypercholesterolemia. The Q192R genotype frequencies were 38% (QQ), 44% (QR), and 18% (RR). We found an association of the 192Q genotype with hypertension. The results of this study signal the importance to evaluate the influence and potential interactions of BChE and PON1 192Q allele with known genetic and environmental factors implicated in the pathogenesis of CVD. PMID:29430251

The structural damages of lens crystallins induced by peroxynitrite and methylglyoxal, two causative players in diabetic complications and preventive role of lens antioxidant components.

PubMed

Moghadam, Sogand Sasan; Oryan, Ahmad; Kurganov, Boris I; Tamaddon, Ali-Mohammad; Alavianehr, Mohammad Mehdi; Moosavi-Movahedi, Ali Akbar; Yousefi, Reza

2017-10-01

Peroxynitrite (PON) and methylglyoxal (MGO), two diabetes-associated compounds, are believed to be important causative players in development of diabetic cataracts. In the current study, different spectroscopic methods, gel electrophoresis, lens culture and microscopic assessments were applied to examine the impact of individual, subsequent or simultaneous modification of lens crystallins with MGO and PON on their structure, oligomerization and aggregation. The protein modifications were confirmed with detection of the significantly increased quantity of carbonyl groups and decreased levels of sulfhydryl, tyrosine and tryptophan. Also, lens proteins modification with these chemical agents was accompanied with important structural alteration, oligomerization, disulfide/chromophore mediated protein crosslinking and important proteolytic instability. All these structural damages were more pronounced when the lens proteins were modified in the presence of both mentioned chemical agents, either in sequential or simultaneous manner. Ascorbic acid and glutathione, as the main components of lens antioxidant defense mechanism, were also capable to markedly prevent the damaging effects of PON and MGO on lens crystallins, as indicated by gel electrophoresis. The results of this study may highlight the importance of lens antioxidant defense system in protection of crystallins against the structural insults induced by PON and MGO during chronic hyperglycemia in the diabetic patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence on serum asymmetric dimethylarginine (ADMA) concentrations of human paraoxonase 1 polymorphism (Q192R) and exposure to polycyclic aromatic hydrocarbons (PAHs) in Mexican women, a gene-environment interaction.

PubMed

Ochoa-Martínez, Ángeles C; Ruíz-Vera, Tania; Almendarez-Reyna, Claudia I; Orta-García, Sandra T; Pérez-Maldonado, Iván N

2017-11-01

It has been demonstrated that Cardiovascular Diseases (CVD) are a consequence of the combination of genetic and environmental factors and/or the interaction between them. Therefore, the aim of this study was to evaluate the impact of polycyclic aromatic hydrocarbon (PAHs) exposure and PON1 Q192R polymorphism (genetic susceptibility) on serum asymmetric dimethylarginine (ADMA) levels in Mexican women (n = 206). Urinary 1-hydroxypyrene concentrations (1-OHP; exposure biomarker for PAHs) were quantified using a high-performance liquid chromatography technique, PON1 Q192R polymorphism was genotyped using TaqMan probes and serum ADMA concentrations were evaluated using a commercially available ELISA kit. Urinary 1-OHP levels detected in this study ranged from 0.07 to 9.37 μmol/mol of creatinine (0.13-18.0 μg/g of creatinine). Regarding allele frequency (PON1 Q192R polymorphism), the 192Q-allele frequency was 0.43 and for the 192R-allele it was 0.57. In relation to serum ADMA levels, the levels ranged from 0.06 to 1.46 μmol/L. Moreover, multiple linear regression analysis was performed and associations between urinary 1-OHP levels (β = 0.05, p = 0.002), PON1 Q192R polymorphism (β = 0.04, p = 0.003) and serum ADMA concentrations were found. Besides, an interaction (gene-environment interaction) of both independent variables (1-OHP and PON1 polymorphism) on serum ADMA levels was found (β = 0.04, p = 0.02) in the constructed multiple linear model. Therefore, according to the significance of this research, it is necessary to execute health programs to reduce cardiovascular risk in the assessed population. Copyright © 2017 Elsevier Ltd. All rights reserved.

A novel survivable WDM passive optical networks

NASA Astrophysics Data System (ADS)

Cheng, Xiaofei; Fang, Qin; Zhang, Yong; Chen, Bin; Lu, Fucai

2008-11-01

We propose a novel survivable wavelength-division multiplexed-passive optical network (WDM-PON) based on an N × N cyclic array waveguide grating (AWG) and reflective semiconductor optical amplifiers (RSOAs). ONUs are grouped and connected with extra connection fibres (CFs). Protection resources are provided mutually in ONU pairs. The characteristics of the proposed survivable WDM-PON and wavelength routing scheme are analyzed. Experiments of 10- Gb/s downstream and 1.25-Gb/s upstream transmission experiments are demonstrated to verify our proposed scheme.

Purification and Characterization of Functional Human Paraoxonase-1 Expressed in Trichoplusia ni Larvae

DTIC Science & Technology

2010-01-01

purified from Trichoplusia ni (T. ni) larvae infected with an orally active form of bac- ulovirus. SDS-PAGE and anti-HuPON1 Western blot analyses yielded...Organophosphorus (OP) nerve agents readily bind covalently o acetylcholinesterase (AChE) at the active site serine and inhibit he ability of AChE to terminate...The results demon- trate that T. ni larvae are capable of producing high quantities of unctionally active recombinant HuPON1, and larvae expressing

Study of dual-polarization OQAM-OFDM PON with direct detection

NASA Astrophysics Data System (ADS)

Luo, Qing-long; Feng, Min; Bai, Cheng-lin; Hu, Wei-sheng

2016-01-01

An offset quadrature amplitude modulation orthogonal frequency-division multiplexing (OQAM-OFDM) passive optical network (PON) architecture with direct detection is brought up to increase the transmission range and improve the system performance. In optical line terminal (OLT), OQAM-OFDM signals at 40 Gbit/s are transmitted as downstream. At each optical network unit (ONU), the optical OQAM-OFDM signal is demodulated with direct detection. The results show that the transmission distance can exceed 20 km with negligible penalty under the experimental conditions.

The Maritime Environment, International Conference and Exhibition "Waste Water Treatment Technologies for Ships"

DTIC Science & Technology

1998-01-01

PEN 00 IJJ0 * PO PCg 0 M1 PM10 0M PON 0 PON *-4-) *% z * FIN* 0 -m PENA wo roe PORN OPW Ina 0 POO 0 Poo u U 0 ; 4-o sow 0P.4 P.4 OPM40 Poo Pssm-+NaPMO...than trying to guarantee, that even our children’s children can still enjoy beaches like this DEE -SYSE - MCL ’ESTPASSEGSA D-26120LZOEN I-RC ST eeon

Physical-Layer Network Coding for VPN in TDM-PON

NASA Astrophysics Data System (ADS)

Wang, Qike; Tse, Kam-Hon; Chen, Lian-Kuan; Liew, Soung-Chang

2012-12-01

We experimentally demonstrate a novel optical physical-layer network coding (PNC) scheme over time-division multiplexing (TDM) passive optical network (PON). Full-duplex error-free communications between optical network units (ONUs) at 2.5 Gb/s are shown for all-optical virtual private network (VPN) applications. Compared to the conventional half-duplex communications set-up, our scheme can increase the capacity by 100% with power penalty smaller than 3 dB. Synchronization of two ONUs is not required for the proposed VPN scheme

Reliable Wide-Area Wavelength Division Multiplexing Passive Optical Network Accommodating Gigabit Ethernet and 10-Gb Ethernet Services

NASA Astrophysics Data System (ADS)

Nakamura, Hirotaka; Suzuki, Hiro; Kani, Jun-Ichi; Iwatsuki, Katsumi

2006-05-01

This paper proposes and demonstrates a reliable wide-area wavelength-division-multiplexing passive optical network (WDM-PON) with a wavelength-shifted protection scheme. This protection scheme utilizes the cyclic property of 2 × N athermal arrayed-waveguide grating and two kinds of wavelength allocations, each of which is assigned for working and protection, respectively. Compared with conventional protection schemes, this scheme does not need a 3-dB optical coupler, thus leading to ensure the large loss budget that is suited for wide-area WDM-PONs. It also features a passive access node and does not have a protection function in the optical network unit (ONU). The feasibility of the proposed scheme is experimentally confirmed by the carrier-distributed WDM-PON with gigabit Ethernet interface (GbE-IF) and 10-GbE-IF, in which the ONU does not employ a light source, and all wavelengths for upstream signals are centralized and distributed from the central office.

Upgrade of an optical network unit in a 40 Gb/s time and wavelength-division multiplexed passive optical network using an upstream tunable colorless laser

NASA Astrophysics Data System (ADS)

Bindhaiq, Salem; Supa'at, Abu Sahmah M.; Zulkifli, Nadiatulhuda; Shaddad, Redhwan Q.; Mataria, Abdallah

2014-07-01

A high data transmission rate is the main requirement for next-generation telecommunication networks. A design for a 40 Gb/s time and wavelength-division multiplexed passive optical network (TWDM-PON) for next-generation passive optical network stage 2 is presented. The use of a modulated grating Y-branch (MG-Y) laser is proposed as an upstream tunable colorless laser source to upgrade the optical network unit. The electronically tuned MG-Y externally modulated laser with a 10 Gb/s modulation rate is applied to a TWDM-PON and presented across a 3.2-nm tuning range. The performance of the proposed laser is analyzed in terms of bit error rate, eye diagram, and optical signal-to-noise ratio. The proposed TWDM-PON achieved an aggregated data rate of 40 Gb/s along 40 km of bidirectional fiber at a 1:128 splitting ratio without amplification and dispersion compensation.

Electroabsorption-modulated widely tunable DBR laser transmitter for WDM-PONs.

PubMed

Han, Liangshun; Liang, Song; Wang, Huitao; Qiao, Lijun; Xu, Junjie; Zhao, Lingjuan; Zhu, Hongliang; Wang, Baojun; Wang, Wei

2014-12-01

We present an InP based distributed Bragg reflector (DBR) laser transmitter which has a wide wavelength tuning range and a high chip output power for wavelength division multiplexing passive optical network (WDM-PON) applications. By butt-jointing InGaAsP with 1.45 µm emission wavelength as the material of the grating section, the laser wavelength can be tuned for over 13 nm by the DBR current. Accompanied by varying the chip temperature, the tuning range can be further enlarged to 16 nm. With the help of the integrated semiconductor optical amplifier (SOA), the largest chip output power is over 30 mW. The electroabsorption modulator (EAM) is integrated into the device by the selective-area growth (SAG) technique. The 3 dB small signal modulation bandwidth of the EAM is over 13 GHz. The device has both a simple tuning scheme and a simple fabrication procedure, making it suitable for low cost massive production which is desirable for WDM-PON uses.

Hybrid scheduling mechanisms for Next-generation Passive Optical Networks based on network coding

NASA Astrophysics Data System (ADS)

Zhao, Jijun; Bai, Wei; Liu, Xin; Feng, Nan; Maier, Martin

2014-10-01

Network coding (NC) integrated into Passive Optical Networks (PONs) is regarded as a promising solution to achieve higher throughput and energy efficiency. To efficiently support multimedia traffic under this new transmission mode, novel NC-based hybrid scheduling mechanisms for Next-generation PONs (NG-PONs) including energy management, time slot management, resource allocation, and Quality-of-Service (QoS) scheduling are proposed in this paper. First, we design an energy-saving scheme that is based on Bidirectional Centric Scheduling (BCS) to reduce the energy consumption of both the Optical Line Terminal (OLT) and Optical Network Units (ONUs). Next, we propose an intra-ONU scheduling and an inter-ONU scheduling scheme, which takes NC into account to support service differentiation and QoS assurance. The presented simulation results show that BCS achieves higher energy efficiency under low traffic loads, clearly outperforming the alternative NC-based Upstream Centric Scheduling (UCS) scheme. Furthermore, BCS is shown to provide better QoS assurance.

Performance investigation of optical multicast overlay system using orthogonal modulation format

NASA Astrophysics Data System (ADS)

Singh, Simranjit; Singh, Sukhbir; Kaur, Ramandeep; Kaler, R. S.

2015-03-01

We proposed a bandwidth efficient wavelength division multiplexed-passive optical network (WDM-PON) to simultaneously transmit 60 Gb/s unicast and 10 Gb/s multicast services with 10 Gb/s upstream. The differential phase shift keying (DPSK) multicast signal is superimposed onto multiplexed non-return to zero/polarization shift keying (NRZ/PolSK) orthogonal modulated data signals. Upstream amplitude shift keying (ASK) signals formed without use of any additional light source and superimposed onto received unicast NRZ/PolSK signal before being transmitted back to optical line terminal (OLT). We also investigated the proposed WDM-PON system for variable optical input power, transmission distance of single mode fiber in multicast enable and disable mode. The measured Quality factor for all unicast and multicast signal is in acceptable range (>6). The original contribution of this paper is to propose a bandwidth efficient WDM-PON system that could be projected even in high speed scenario at reduced channel spacing and expected to be more technical viable due to use of optical orthogonal modulation formats.

Improving upstream transmission performance using a receiver with decision threshold level adjustment in a loopback WDM-PON

NASA Astrophysics Data System (ADS)

Cho, Seung-Hyun; Lee, Sang-Soo; Shin, Dong-Wook

2010-06-01

We have experimentally demonstrated that the use of an optical receiver with decision threshold level adjustment (DTLA) improved the performance of an upstream transmission in reflective semiconductor optical amplifier (RSOA)-based loopback wavelength division multiplexing-passive optical network (WDM-PON). Even though the extinction ratio (ER) of the downstream signal was as much as 9 dB and the injection power into the RSOA at the optical network unit was about -24 dBm, we successfully obtained error-free transmission results for the upstream signal through careful control of the decision threshold value in the optical receiver located at optical line terminal (OLT). Using an optical receiver with DTLA for upstream signal detection overcame significant obstacles related to the injection power into the RSOA and the ER of the downstream signal, which were previously considered limitations of the wavelength remodulation scheme. This technique is expected to provide flexibility for the optical link design in the practical deployment of a WDM-PON.

Compensation of power drops in reflective semiconductor optical amplifier-based passive optical network with upstream data rate adjustment

NASA Astrophysics Data System (ADS)

Yeh, Chien-Hung; Chow, Chi-Wai; Chiang, Ming-Feng; Shih, Fu-Yuan; Pan, Ci-Ling

2011-09-01

In a wavelength division multiplexed-passive optical network (WDM-PON), different fiber lengths and optical components would introduce different power budgets to different optical networking units (ONUs). Besides, the power decay of the distributed optical carrier from the optical line terminal owing to aging of the optical transmitter could also reduce the injected power into the ONU. In this work, we propose and demonstrate a carrier distributed WDM-PON using a reflective semiconductor optical amplifier-based ONU that can adjust its upstream data rate to accommodate different injected optical powers. The WDM-PON is evaluated at standard-reach (25 km) and long-reach (100 km). Bit-error rate measurements at different injected optical powers and transmission lengths show that by adjusting the upstream data rate of the system (622 Mb/s, 1.25 and 2.5 Gb/s), error-free (<10-9) operation can still be achieved when the power budget drops.

Optimization model for UDWDM-PON deployment based on physical restrictions and asymmetric user's clustering

NASA Astrophysics Data System (ADS)

Arévalo, Germán. V.; Hincapié, Roberto C.; Sierra, Javier E.

2015-09-01

UDWDM PON is a leading technology oriented to provide ultra-high bandwidth to final users while profiting the physical channels' capability. One of the main drawbacks of UDWDM technique is the fact that the nonlinear effects, like FWM, become stronger due to the close spectral proximity among channels. This work proposes a model for the optimal deployment of this type of networks taking into account the fiber length limitations imposed by physical restrictions related with the fiber's data transmission as well as the users' asymmetric distribution in a provided region. The proposed model employs the data transmission related effects in UDWDM PON as restrictions in the optimization problem and also considers the user's asymmetric clustering and the subdivision of the users region though a Voronoi geometric partition technique. Here it is considered de Voronoi dual graph, it is the Delaunay Triangulation, as the planar graph for resolving the problem related with the minimum weight of the fiber links.

Next-generation bidirectional Triple-play services using RSOA based WDM Radio on Free-Space Optics PON

NASA Astrophysics Data System (ADS)

Mandal, Gour Chandra; Mukherjee, Rahul; Das, Binoy; Patra, Ardhendu Sekhar

2018-03-01

An innovative low cost reflective semiconductor amplifier (RSOA) based bidirectional Triple-play services (TPS) using wavelength division multiplexed radio on free-space-optics passive optical network (WDM-RoFSO-PON) is proposed and experimentally demonstrated to transmit data, voice and video services simultaneously. In this paper, the TPS (10 Gb/s data/voice and 1.49 Gb/s HDTV signal) are successfully transmitted over a 500 m free-space link in downstream and RSOA is utilized at the receiving site to broadcast 1.25 Gb/s data/voice signal over same free-space link in upstream by reusing the carrier, that makes the system cost-effective. High receiver sensitivity and signal-to-noise ratio (SNR), low bit-error-rate (BER) and low error vector magnitude (EVM), and excellent eye-diagrams in our proposed network build the system more reliable and stable with acceptable performance. Therefore, proposed WDM-RoFSO-PON could be the viable solution for future ubiquitous multiservice wireless network in the scenario of TPS.

In vitro inhibitory effects of palonosetron hydrochloride, bevacizumab and cyclophosphamide on purified paraoxonase-I (hPON1) from human serum.

PubMed

Türkeş, Cüneyt; Söyüt, Hakan; Beydemir, Şükrü

2016-03-01

In this study, we investigated the effects of the drugs, palonosetron hydrochloride, bevacizumab and cyclophosphamide, on human serum paraoxonase-I (hPON1) enzyme activity in in vitro conditions. The enzyme was purified ∼231-fold with 34.2% yield by using ammonium sulphate precipitation, DEAE-Sephadex A-50 ion-exchange chromatography and Sephadex G-200 gel-filtration chromatography from human serum. hPON1 exhibited a single protein band on the SDS polyacrylamide gel electrophoresis. The inhibition studies were performed on paraoxonase activity of palonosetron hydrochloride, bevacizumab and cyclophosphamide. Ki constants were found as 0.033±0.001, 0.054±0.003 mM and 3.419±0.518 mM, respectively. Compared to the inhibition rates of the drugs, palonosetron hydrochloride has the maximum inhibition rate. However, inhibition mechanisms of the drugs were determined as noncompetitive by Lineweaver-Burk curves. Copyright © 2016 Elsevier B.V. All rights reserved.

C-fos expression in the pons and medulla of the cat during carbachol-induced active sleep.

PubMed

Yamuy, J; Mancillas, J R; Morales, F R; Chase, M H

1993-06-01

Microinjection of carbachol into the rostral pontine tegmentum of the cat induces a state that is comparable to naturally occurring active (REM, rapid eye movement) sleep. We sought to determine, during this pharmacologically induced behavioral state, which we refer to as active sleep-carbachol, the distribution of activated neuron within the pons and medulla using c-fos immunocytochemistry as a functional marker. Compared with control cats, which were injected with saline, active sleep-carbachol cats exhibited higher numbers of c-fos-expressing neurons in (1) the medial and portions of the lateral reticular formation of the pons and medulla, (2) nuclei in the dorsolateral rostral pons, (3) various raphe nuclei, including the dorsal, central superior, magnus, pallidus, and obscurus, (4) the medial and lateral vestibular, prepositus hypoglossi, and intercalatus nuclei, and (5) the abducens nuclei. On the other hand, the mean number of c-fos-expressing neurons found in the masseter, facial, and hypoglossal nuclei was lower in carbachol-injected than in control cats. The data indicate that c-fos expression can be employed as a marker of state-dependent neuronal activity. The specific sites in which there were greater numbers of c-fos-expressing neurons during active sleep-carbachol are discussed in relation to the state of active sleep, as well as the functional role that these sites play in generating the various physiological patterns of activity that occur during this state.

Pontine norepinephrine content after motor cortical ablation in rats.

PubMed

Gonzalez-Pina, Rigoberto; Bueno-Nava, Antonio; Montes, Sergio; Alfaro-Rodriguez, Alfonso; Gonzalez-Maciel, Angélica; Reynoso-Robles, Rafael; Ayala-Guerrero, Fructuoso

2005-01-01

It has been reported that norepinephrine (NE) plays an important role in recovery after brain damage. However, the role of the pons, the site where the norepinephrinergic locus coeruleus (LC) is located, has not been elucidated. In order to study the changes in the pontine NE content in either noninjured, injured or recovered rats, we used 35 animals trained to walk across to a walkway where their footprints were recorded. Subsequently, 17 trained rats were sham-operated while 18 were injured by means of an ablation of the right motor cortex representative of the hindlimb. From the injured rats, 6 were sacrificed 6 hr before surgery in order to obtain the pons, while all the remaining rats were recorded in the walkway 6, 24 and 48 hr post-surgery. Then, rats were sacrificed by decapitation, the pons was removed and each hemisphere was prepared for the chromatographic analysis of NE. Results showed that after cortical brain damage, the length of the stride decreased while the angle of the stride increased 6 hr post-surgery. Recovery was observed after 24 hr. NE increased in the pons after 6 hr and returned to normal levels when rats had recovered. This suggests that cortical damage elicits NE changes in the LC that could reorganize the system to lead the recovery process. Such findings must be taken in account when pharmacotherapy with antidepressants or antipsychotics that act on norepinephrine-containing neuronal systems are prescribed in patients after stroke.

Effects of feedborne fusarium mycotoxins on brain regional neurochemistry of turkeys.

PubMed

Girish, C K; MacDonald, E J; Scheinin, M; Smith, T K

2008-07-01

An experiment was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on brain regional neurochemistry of turkeys. The possible preventative effect of a poly-meric glucomannan mycotoxin adsorbent (GMA) was also determined. Forty-five 1-d-old male turkey poults were fed wheat-, corn-, and soybean meal-based diets up to wk 6, formulated with control grains, contaminated grains, or contaminated grains + 0.2% GMA. Deoxynivalenol was the major contaminant, and the concentrations were 2.2 and 3.3 mg/kg of feed during starter and grower phases, respectively. Concentrations of brain monoamine neurotransmitters and metabolites were measured in discrete regions of the brain including the pons, hypothalamus, and cortex by HPLC with electrochemical detection. Neurotransmitters and metabolites analyzed included norepinephrine, dopamine, 3,4-dihydroxyphenylacetic acid, serotonin (5-hydroxytryptamine, 5-HT), and 5-hydroxyindoleacetic acid (5-HIAA). The concentration of 5-HIAA and the 5-HIAA:5-HT-ratio were significantly decreased in pons after feeding contaminated grains. Dietary supplementation with GMA prevented these effects. In the pons, a significant positive correlation (r = 0.52, P < 0.05) was observed between the concentration of 5-HT and BW gain after feeding contaminated diets. The feeding of contaminated diet had no significant effects on the concentrations of neurotransmitters and metabolites in hypothalamus and cortex. It was concluded that consumption of grains naturally contaminated with Fusarium mycotoxins adversely altered the pons serotonergic system of turkeys. Supplementation with GMA partially inhibited these effects.

Optical fiber-fault surveillance for passive optical networks in S-band operation window

NASA Astrophysics Data System (ADS)

Yeh, Chien-Hung; Chi, Sien

2005-07-01

An S-band (1470 to 1520 nm) fiber laser scheme, which uses multiple fiber Bragg grating (FBG) elements as feedback elements on each passive branch, is proposed and described for in-service fault identification in passive optical networks (PONs). By tuning a wavelength selective filter located within the laser cavity over a gain bandwidth, the fiber-fault of each branch can be monitored without affecting the in-service channels. In our experiment, an S-band four-branch monitoring tree-structured PON system is demonstrated and investigated experimentally.

Bi-wavelength two dimensional chirped grating couplers for low cost WDM PON transceivers

NASA Astrophysics Data System (ADS)

Xu, Lin; Chen, Xia; Li, Chao; Tsang, Hon Ki

2011-04-01

We propose and demonstrate a bi-wavelength two dimensional (2D) waveguide grating coupler on silicon-on-insulator which has efficient coupling of optical light with two-wavelength bands independently between standard optical single mode fibers and nanophotonic waveguides. The details of design are described and the measurement results as well as system performance are experimentally characterized. The bi-wavelength grating coupler can be used as wavelength-division-multiplexing (WDM) splitter/combiner for monolithically silicon integrated transceivers, potentially meeting the low cost requirements for future WDM passive optical network (PON).

Long reach DWDM-PON with 12.5 GHz channel spacing based on comb source seeding

NASA Astrophysics Data System (ADS)

Zhou, Zhao; Nie, Hai-tao; Wang, Yao-jun

2016-07-01

A long reach dense wavelength division multiplexing passive optical network (DWDM-PON) with 12.5 GHz channel spacing is proposed and experimentally demonstrated. An optical frequency comb source is used to provide the multiwavelength seeding light, while reflective semiconductor optical amplifiers (RSOAs) are installed in both optical line terminal (OLT) and optical network units (ONUs) as colorless transmitter. The experimental results show that the bidirectional transmission for 1.2 Gbit/s data rate is achieved over 80 km single mode fiber (SMF).

Self-healing ring-based WDM-PON

NASA Astrophysics Data System (ADS)

Zhou, Yang; Gan, Chaoqin; Zhu, Long

2010-05-01

In this paper, a survivable ring-based wavelength-division-multiplexing (WDM)-passive optical network (PON) for fiber protection is proposed. Protections for feeder fiber and distributed fiber are independent in the scheme. Optical line terminal (OLT) and optical network units (ONUs) can automatically switch to protection link when fiber failure occurs. Protection distributed fiber is not required in the scheme. Cost-effective components are used in ONUs to minimize costs of network. A simulation study is performed to demonstrate the scheme. Its result shows good performance of upstream and downstream signals.

First demonstration and field trial on multi-user UDWDM-PON full duplex PSK-PSK with single monolithic integrated dual-output-DFB-SOA based ONUs.

PubMed

Chu, GuangYong; Maho, Anaëlle; Cano, Iván; Polo, Victor; Brenot, Romain; Debrégeas, Hélène; Prat, Josep

2016-10-15

We demonstrate a monolithically integrated dual-output DFB-SOA, and conduct the field trial on a multi-user bidirectional coherent ultradense wavelength division multiplexing-passive optical network (UDWDM-PON). To the best of our knowledge, this is the first achievement of simplified single integrated laser-based neighboring coherent optical network units (ONUs) with a 12.5 GHz channel spaced ultra-dense access network, including both downstream and upstream, taking the benefits of low footprint and low-temperature dependence.

Assessing Protection Against OP Pesticides and Nerve Agents Provided by Wild-Type HuPON1 Purified from Trichoplusia ni Larvae or Induced via Adenoviral Infection

DTIC Science & Technology

2013-01-01

times the median lethal dose (LD50) of the OP nerve agents tabun (GA), sarin (GB), soman (GD), and cyclosarin (GF), or chlorpyrifos oxon, the toxic...metabolite of the OP pesticide chlorpyrifos . In the second model, mice were infected with an adenovirus that induced expression of HuPON1 and then...mice are dramati- cally more susceptible to the toxic metabolites of the OP pesticides diazinon and chlorpyrifos (diazoxon and chlorpyrifos oxon

Optical fiber-fault surveillance for passive optical networks in S-band operation window.

PubMed

Yeh, Chien-Hung; Chi, Sien

2005-07-11

An S-band (1470 to 1520 nm) fiber laser scheme, which uses multiple fiber Bragg grating (FBG) elements as feedback elements on each passive branch, is proposed and described for in-service fault identification in passive optical networks (PONs). By tuning a wavelength selective filter located within the laser cavity over a gain bandwidth, the fiber-fault of each branch can be monitored without affecting the in-service channels. In our experiment, an S-band four-branch monitoring tree-structured PON system is demonstrated and investigated experimentally.

Associations of maternal organophosphate pesticide exposure and PON1 activity with birth outcomes in SAWASDEE birth cohort, Thailand

PubMed Central

Naksen, Warangkana; Prapamontol, Tippawan; Mangklabruks, Ampica; Chantara, Somporn; Thavornyutikarn, Prasak; Srinual, Niphan; Panuwet, Parinya; Ryan, P. Barry; Riederer, Anne M.; Barr, Dana Boyd

2015-01-01

Prenatal organophosphate (OP) pesticide exposure has been reported to be associated with adverse birth outcomes and neurodevelopment. However, the mechanisms of toxicity of OP pesticides on human fetal development have not yet been elucidated. Our pilot study birth cohort, the Study of Asian Women and Offspring’s Development and Environmental Exposures (SAWASDEE cohort) aimed to evaluate environmental chemical exposures and their relation to birth outcomes and infant neurodevelopment in 52 pregnant farmworkers in Fang district, Chiang Mai province, Thailand. A large array of data was collected multiple times during pregnancy including approximately monthly urine samples for evaluation of pesticide exposure, three blood samples for pesticide-related enzyme measurements and questionnaire data. This study investigated the changes in maternal acetylcholinesterase (AChE) and paraoxonase 1 (PON1) activities and their relation to urinary diakylphosphates (DAPs), class-related metabolites of OP pesticides, during pregnancy. Maternal AChE, butyrylcholinesterase (BChE) and PON1 activities were measured three times during pregnancy and urinary DAP concentrations were measured, on average, 8 times from enrollment during pregnancy until delivery. Among the individuals in the group with low maternal PON1 activity (n = 23), newborn head circumference was negatively correlated with log10 maternal ΣDEAP and ΣDAP at enrollment (gestational age=12±3 weeks; β = −1.0 cm, p = 0.03 and β = −1.8 cm, p <0.01, respectively) and at 32 weeks pregnancy (β = −1.1 cm, p = 0.04 and β = −2.6 cm, p = 0.01, respectively). Furthermore, among these mothers, newborn birthweight was also negatively associated with log10 maternal ΣDEAP and ΣDAP at enrollment (β = −219.7 g, p = 0.05 and β = −371.3 g, p = 0.02, respectively). Associations between maternal DAP levels and newborn outcomes were not observed in the group of participants with high maternal PON1 activity. Our results support previous findings from US birth cohort studies. This is the first study to report the associations between prenatal OP pesticide exposure and birth outcomes in Thailand. PMID:26186137

High triglycerides and low high-density lipoprotein cholesterol lipid profile in rheumatoid arthritis: A potential link among inflammation, oxidative status, and dysfunctional high-density lipoprotein.

PubMed

Rodríguez-Carrio, Javier; Alperi-López, Mercedes; López, Patricia; López-Mejías, Raquel; Alonso-Castro, Sara; Abal, Francisco; Ballina-García, Francisco J; González-Gay, Miguel Á; Suárez, Ana

The interactions between inflammation and lipid profile in rheumatoid arthritis (RA) are poorly understood. The lipid profile study in RA has been biased toward lipoprotein levels, whereas those of triglycerides (TGs) and lipoprotein functionality have been underestimated. Since recent findings suggest a role for TG and TG-rich lipoproteins (TRL) on inflammation, we aimed to evaluate a combined lipid profile characterized by high TG and low high-density lipoprotein cholesterol levels (TG high HDL low ) in RA. Lipid profiles were analyzed in 113 RA patients, 113 healthy controls, and 27 dyslipemic subjects. Levels of inflammatory mediators, paraoxonase-1 (PON1) activity, and total antioxidant capacity were quantified in serum. PON1-rs662 status was evaluated by real-time polymerase chain reaction. The TG high HDL low profile was detected in 29/113 RA patients. Although no differences in prevalence compared with healthy controls or dyslipemic subjects were observed, this profile was associated with increased tumor necrosis factor α (P = .004), monocyte chemotactic protein (P = .004), interferon-gamma-inducible protein-10 (P = .018), and leptin (P < .001) serum levels in RA, where decreased PON1 activity and total antioxidant capacity were found. TG high HDL low prevalence was lower among anti-TNFα-treated patients (P = .004). When RA patients were stratified by PON1-rs662 status, these associations remained in the low-activity genotype (QQ). Finally, a poor clinical response on TNFα blockade was related to an increasing prevalence of the TG high HDL low profile over treatment (P = .021) and higher TRL levels at baseline (P = .042). The TG high HDL low profile is associated with systemic inflammation, decreased PON1 activity, and poor clinical outcome on TNFα blockade in RA, suggesting a role of TRL and HDL dysfunction as the missing link between inflammation and lipid profile. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Association of RAGE gene polymorphism with circulating AGEs level and paraoxonase activity in relation to macro-vascular complications in Indian type 2 diabetes mellitus patients.

PubMed

Bansal, Savita; Chawla, Diwesh; Banerjee, Basu Dev; Madhu, Sri Venkata; Tripathi, Ashok Kumar

2013-09-10

Sustained interaction of advanced glycation end products (AGEs) with their receptor RAGE and subsequent signaling plays an important role in the development of diabetic complications. Genetic variation of RAGE gene may be associated with the development of vascular complications in type 2 diabetes mellitus (T2DM). The present study aimed to explore the possible association of RAGE gene polymorphisms namely -374T/A, -429T/C and G82S with serum level of AGEs, paraoxonase (PON1) activity and macro-vascular complications (MVC) in Indian type 2 diabetes mellitus patients (T2DM). A total of 265 diabetic patients, including DM without any complications (n=135), DM-MVC (n=130) and 171 healthy individuals were enrolled. Genotyping of RAGE variants were assessed by polymerase chain reaction-restriction fragment length polymorphism. Serum AGEs were estimated by ELISA and fluorometrically. and PON1 activity was assessed spectrophotometrically. Of the three examined SNPs, association of -429T/C polymorphism with MVC in T2DM was observed (OR=3.001, p=0.001) in the dominant model. Allele 'A' of -374T/A polymorphism seems to confer better cardiac outcome in T2DM. Patients carrying C allele (-429T/C) and S allele (G82S) had significantly higher AGEs levels. -429T/C polymorphism was also found to be associated with low PON1 activity. Interaction analysis revealed that the risk of development of MVC was higher in T2DM patients carrying both a CC genotype of -429T/C polymorphism and a higher level of AGEs (OR=1.343, p=0.040). RAGE gene polymorphism has a significant effect on AGEs level and PON1 activity in diabetic subjects compared to healthy individuals. Diabetic patients with a CC genotype of -429T/C are prone to develop MVC, more so if AGEs levels are high and PON1 activity is low. Copyright © 2013 Elsevier B.V. All rights reserved.

Associations of maternal organophosphate pesticide exposure and PON1 activity with birth outcomes in SAWASDEE birth cohort, Thailand.

PubMed

Naksen, Warangkana; Prapamontol, Tippawan; Mangklabruks, Ampica; Chantara, Somporn; Thavornyutikarn, Prasak; Srinual, Niphan; Panuwet, Parinya; Ryan, P Barry; Riederer, Anne M; Barr, Dana Boyd

2015-10-01

Prenatal organophosphate (OP) pesticide exposure has been reported to be associated with adverse birth outcomes and neurodevelopment. However, the mechanisms of toxicity of OP pesticides on human fetal development have not yet been elucidated. Our pilot study birth cohort, the Study of Asian Women and Offspring's Development and Environmental Exposures (SAWASDEE cohort) aimed to evaluate environmental chemical exposures and their relation to birth outcomes and infant neurodevelopment in 52 pregnant farmworkers in Fang district, Chiang Mai province, Thailand. A large array of data was collected multiple times during pregnancy including approximately monthly urine samples for evaluation of pesticide exposure, three blood samples for pesticide-related enzyme measurements and questionnaire data. This study investigated the changes in maternal acetylcholinesterase (AChE) and paraoxonase 1 (PON1) activities and their relation to urinary diakylphosphates (DAPs), class-related metabolites of OP pesticides, during pregnancy. Maternal AChE, butyrylcholinesterase (BChE) and PON1 activities were measured three times during pregnancy and urinary DAP concentrations were measured, on average, 8 times from enrollment during pregnancy until delivery. Among the individuals in the group with low maternal PON1 activity (n=23), newborn head circumference was negatively correlated with log10 maternal ∑DEAP and ∑DAP at enrollment (gestational age=12±3 weeks; β=-1.0 cm, p=0.03 and β=-1.8 cm, p<0.01, respectively) and at 32 weeks pregnancy (β=-1.1cm, p=0.04 and β=-2.6 cm, p=0.01, respectively). Furthermore, among these mothers, newborn birthweight was also negatively associated with log10 maternal ∑DEAP and ∑DAP at enrollment (β=-219.7 g, p=0.05 and β=-371.3g, p=0.02, respectively). Associations between maternal DAP levels and newborn outcomes were not observed in the group of participants with high maternal PON1 activity. Our results support previous findings from US birth cohort studies. This is the first study to report the associations between prenatal OP pesticide exposure and birth outcomes in Thailand. Copyright © 2015 Elsevier Inc. All rights reserved.

Highly Reliable PON Optical Splitters for Optical Access Networks in Outside Environments

NASA Astrophysics Data System (ADS)

Watanabe, Hiroshi; Araki, Noriyuki; Fujimoto, Hisashi

Broadband optical access services are spreading throughout the world, and the number of fiber to the home (FTTH) subscribers is increasing rapidly. Telecom operators are constructing passive optical networks (PONs) to provide optical access services. Externally installed optical splitters for PONs are very important passive devices in optical access networks, and they must provide satisfactory performance as outdoor plant over long periods. Therefore, we calculate the failure rate of optical access networks and assign a failure rate to the optical splitters in optical access networks. The maximum cumulative failure rate of 1 × 8 optical splitters was calculated as 0.025 for an optical access fiber length of 2.1km and a 20-year operating lifetime. We examined planar lightwave circuit (PLC) type optical splitters for use as outside plant in terms of their optical characteristics and environmental reliability. We confirmed that PLC type optical splitters have sufficient optical performance for a PON splitter and sufficient reliability as outside plant in accordance with ITU-T standard values. We estimated the lifetimes of three kinds of PLC type optical splitters by using accelerated aging tests. The estimated failure rate of these splitters installed in optical access networks was below the target value for the cumulative failure rate, and we confirmed that they have sufficient reliability to maintain the quality of the network service. We developed 1 × 8 optical splitter modules with plug and socket type optical connectors and optical fiber cords for optical aerial closures designed for use as outside plant. These technologies make it easy to install optical splitters in an aerial optical closure. The optical splitter modules have sufficient optical performance levels for PONs because the insertion loss at the commercially used wavelengths of 1.31 and 1.55µm is less than the criterion established by ITU-T Recommendation G.671 for optical splitters. We performed a temperature cycling test, and a low temperature storage and damp heat test to confirm the long-term reliability of these modules. They exhibited sufficient reliability as regards heat and moisture because the maximum loss change was less than 0.3dB.

Industrial application of selected lactic acid bacteria isolated from local semolinas for typical sourdough bread production.

PubMed

Corona, Onofrio; Alfonzo, Antonio; Ventimiglia, Giusi; Nasca, Anna; Francesca, Nicola; Martorana, Alessandra; Moschetti, Giancarlo; Settanni, Luca

2016-10-01

Four obligate heterofermentative lactic acid bacteria (LAB) strains (Weissella cibaria PON10030 and PON10032 and Leuconostoc citreum PON 10079 and PON10080) were tested as single strain starters, mono-species dual strain starters, and multiple strain starter for the preparation and propagation of sourdoughs for the production of a typical bread at industrial level. The kinetics of pH and TTA during the daily sourdough refreshments indicated a correct acidification process for all trials. The concentration of lactic and acetic acid increased consistently during fermentation. The resulting molar ratios between these two organic acids in the experimental trials were lower than those observed in the control trial. The microbiological investigation showed levels of approximately 10(9) CFU/mL in almost all sourdoughs and the comparison of the genetic polymorphisms of the dominating LAB with those of the pure cultures evidenced the persistence of the added strains over time. The resulting breads were evaluated for several quality parameters. The breads with the greatest height were obtained with the quadruple combination of leuconostocs and weissellas. The highest softness was registered for the breads obtained from fermentations performed by W. cibaria PON10032 alone and in combination. The different inocula influenced also the color, the void fraction, the cell density and the mean cell area of the breads. Different levels of acids, alcohols, aldehydes, esters, hydrocarbons, ketones, terpenes, furans and phenol were emitted by the breads. The sensory tests indicated the breads from the sourdoughs fermented with the seven LAB inocula as sweeter and less acidic than control breads and the breads from the trials with the highest complexity of LAB inoculums were those more appreciated by tasters. A multivariate approach found strong differences among the trials. In particular, control breads and the breads obtained with different starter LAB were quite distant and a more strict relation was found among the productions carried out by W. cibaria strains. This study proved the suitability of the selected strains of L. citreum and W. cibaria for industrial-scale level applications in sourdough bread production. Copyright © 2016 Elsevier Ltd. All rights reserved.

[High-density lipoproteins (HDL) size and composition are modified in the rat by a diet supplemented with "Hass" avocado (Persea americana Miller)].

PubMed

Pérez Méndez, Oscar; García Hernández, Lizbeth

2007-01-01

To determine the effects of dietary avocado on HDL structure and their associated enzyme, paraoxonase 1 (PON1). Fifteen Wistar male rats received avocado as part of their daily meal (5 g by 17.5 g chow diet), keeping the caloric intake similar to the control group (n=15) that received their usual chow diet. After 5 weeks, HDL were isolated by sequential ultracentrifugation and their size and chemical composition were analyzed. PON1 was determined in serum spectrophotometrically using phenylacetate as substrate. Rats that received avocado had about 27% lower triglycerides plasma levels whereas their HDL-cholesterol was 17% higher as compared to control group. The mean HDL Stokes diameter was significantly lower in avocado group (11.71 +/- 0.8 vs. 12.27 +/- 0.26 nm, in control group, p < 0.05). The HDL size decrease was associated to a lower content of protein, particularly of apo Al, with a concomitant higher proportion of phospholipids in HDL isolated from avocado group. HDL structural modifications induced by avocado were not related to modifications of LCAT and PLTP activities, but occurred in parallel with higher serum levels of PON1 activity when compared to the controls (57.4 +/- 8.9 vs. 43.0 +/- 5.6 micromol/min/mL serum, p < 0.05). The inclusion of avocado in the diet decreased plasma triglycerides, increased HDL-cholesterol plasma levels and modified HDL structure. The latter effect may enhance the antiatherogenic properties of HDL since PON1 activity also increased as a consequence of avocado.

The far lateral transpontomedullary sulcus approach to pontine cavernous malformations: technical report and surgical results.

PubMed

Abla, Adib A; Benet, Arnau; Lawton, Michael T

2014-09-01

Pontine cavernous malformations (CMs) located on a peripheral pontine surface or the fourth ventricular floor are resectable lesions, but those deep within the pons away from a pial surface are typically observed. However, the anterior bulge of the pons formed by the brachium pontis creates a unique entry point for access to deep pontine lesions from below, working upward through the pontomedullary sulcus. We developed a transpontomedullary sulcus (TPMS) approach to these lesions. The TPMS approach used the far lateral craniotomy and upper vagoaccessory triangle to define the surgical corridor. The entry point was above the olive, lateral to the pyramidal tracts and cranial nerve (CN) VI, above the preolivary sulcus and CN XII, and medial to CNs VII and VIII and CNs IX through XI. Four patients underwent this approach. All presented with hemorrhage and CN VI palsies. All pontine CMs were resected completely. Three patients were improved or unchanged, with good outcomes (modified Rankin Scale score ≤2) in all patients. The central pons remains difficult territory to access, and new surgical corridors are needed. The bulging underbelly of the pons allows access to pontine lesions deep to the pial surface from below. The far lateral TPMS approach is a novel and more direct alternative to the retrosigmoid transmiddle cerebellar peduncle approach. Unlike the retrosigmoid approach, the TPMS approach requires minimal parenchymal transgression and uses a brainstem entry point medial to most lower CNs. Favorable results demonstrate the feasibility of resecting pontine CMs that might have been previously deemed unresectable.

A novel real-time duplex PCR assay for detecting penA and ponA genotypes in Neisseria gonorrhoeae: Comparison with phenotypes determined by the E-test.

PubMed

Vernel-Pauillac, Frédérique; Merien, Fabrice

2006-12-01

For many years, the pathogenic bacterium Neisseria gonorrhoeae, the etiologic agent of gonorrhea, was generally susceptible to penicillin, until the emergence of resistant strains. Well-characterized genetic variations in the penicillin resistance-determining region correlate with decreased susceptibility to penicillin. At least 5 genes (penA, penB, mtrR, ponA, and penC) are involved in the chromosomally mediated resistance to this antibiotic. To date, no development of multiplex PCR assays targeting a range of gonococcal genes and variations as a means of predicting antibiotic resistance has been reported. The aim of this study was to develop a duplex assay using DNA from isolated strains. We describe the development and evaluation on the LightCycler platform of a real-time duplex PCR assay (hybridization probe format) for rapid and specific detection of ponA and penA variations, predicting penicillin susceptibilities. The real-time duplex PCR assay successfully detected variations in ponA and penA genes by use of distinct melting temperatures from a total of 120 Neisseria gonorrhoeae isolates. Moreover, the variation profiles obtained with the real-time PCR and the melting analysis showed good correlation with the pattern of penicillin susceptibility generated with classical antibiograms. Nucleotide sequencing data were in complete agreement with multiplex assay results. The presented assay is suitable for the detection of chromosomally mediated resistant strains of Neisseria gonorrhoeae in genotyping studies and could be valuable in the effective antimicrobial strategy to gonococci.

Real-time dual-polarization transmission based on hybrid optical wireless communications

NASA Astrophysics Data System (ADS)

Sousa, Artur N.; Alimi, Isiaka A.; Ferreira, Ricardo M.; Shahpari, Ali; Lima, Mário; Monteiro, Paulo P.; Teixeira, António L.

2018-01-01

We present experimental work on a gigabit-capable and long-reach hybrid coherent UWDM-PON plus FSO system for supporting different applications over the same fiber infrastructure in the mobile backhaul (MBH) networks. Also, for the first time, we demonstrate a reconfigurable real-time DSP transmission/reception of DP-QPSK signals over standard single-mode fiber (SSMF) and FSO links. The receiver presented is based on a commercial field-programmable gate array (FPGA). The considered communication links are based on 20 UDWDM channels with 625 Mbaud and 2.5 GHz channel spacing. We are able to demonstrate the lowest sampling rate required for digital coherent PON by employing four 1.25 Gsa/s ADCs using an electrical front-end receiver that offers only 1 GHz analog bandwidth. We achieved this by implementing a phase and polarization diversity coherent receiver combined with the DP-QPSK modulation formats. The system performance is estimated in terms of receiver sensitivity. The results show the viability of coherent PON and flexible dual-polarization supported by software-defined transceivers for the MBH.

Elaboration and characterization of a free standing LiSICON membrane for aqueous lithium-air battery

NASA Astrophysics Data System (ADS)

Puech, Laurent; Cantau, Christophe; Vinatier, Philippe; Toussaint, Gwenaëlle; Stevens, Philippe

2012-09-01

In order to develop a LISICON separator for an aqueous lithium-air battery, a thin membrane was prepared by a tape-casting of a Li1.3Al0.3Ti1.7 (PO4)3-AlPO4 based slip followed by a sintering step. By optimizing the grain sizes, the slip composition and the sintering treatment, the mechanical properties were improved and the membrane was reduced to a thickness of down to 40 μm. As a result, the ionic resistance is relatively low, around 38 Ω for a 55 μm membrane of 1 cm2. One side of the membrane was coated with a lithium oxynitrured phosphorous (LiPON) thin film to prevent lithium metal attack. Lithium metal was electrochemically deposited on the LiPON surface from a saturated aqueous solution of LiOH. However, the ionic resistance of the LiPON film, around 67 Ω for a 1.2 μm film of 1 cm2, still causes an important ohmic loss contribution which limits the power performance of a lithium-air battery.

Recent progress in design and hybridization of planar grating-based transceivers

NASA Astrophysics Data System (ADS)

Bidnyk, S.; Pearson, M.; Balakrishnan, A.; Gao, M.

2007-06-01

We report on recent progress in simulations, physical layout, fabrication and hybridization of planar grating-based transceivers for passive optical networks (PONs). Until recently, PON transceivers have been manufactured using bulk micro-optical components. Today, advancements in modeling and simulation techniques has made it possible to design complex elements in the same silica-on silicon PLC platform and create an alternative platform for manufacturing of bi-directional transceivers. In our chips we simulated an integrated chip that monolithically combined planar reflective gratings and cascaded Mach-Zehnder interferometers. We used a combination of the finite element method and beam propagation method to model cascaded interferometers with enhanced coupling coefficients. Our simulations show that low-diffraction order planar reflective gratings, designed for small incidence and reflection angles, possess the required dispersion strength to meet the PON specifications. Subsequently, we created structures for passive alignment and hybridized photodetectors and lasers. We believe that advancements in simulation of planar lightwave circuits with embedded planar reflective gratings will result in displacement of the thin-film filters (TFFs) technology in many applications that require a high degree of monolithic and hybrid integration.

First-principles study of LiPON and related solid electrolytes

NASA Astrophysics Data System (ADS)

Du, Yaojun A.; Holzwarth, N. A. W.

2010-05-01

Lithium phosphorus oxynitride materials have been investigated for many years, especially in relation to the thin-film electrolyte LiPON, developed at Oak Ridge National Laboratory. We have carried out first-principles simulations of related crystalline materials as a first step toward understanding the sources of stability and mechanisms of Li-ion conductivity in these materials. In addition to a comprehensive survey of known crystalline materials related to LiPON, we have also predicted some materials. For example, starting with crystalline LiPO3 which has twisted phosphate chains, we considered the possibility of modifying the structure by substituting N and Li for O. The optimized structures were computed to have regularized phosphate chains which form planar -P-N-P-N- backbones. To the best of our knowledge, the predicted crystals, which we call s1-Li2PO2N with a 24-atom unit cell and s2-Li2PO2N with a 12-atom unit cell, have not yet been observed experimentally. We suggest several possible exothermic reaction pathways to synthesize these crystals.

Optical beat interference noise reduction in OFDMA optical access link using self-homodyne balanced detection

NASA Astrophysics Data System (ADS)

Jung, Sang-Min; Won, Yong-Yuk; Han, Sang-Kook

2013-12-01

A Novel technique for reducing the OBI noise in optical OFDMA-PON uplink is presented. OFDMA is a multipleaccess/ multiplexing scheme that can provide multiplexing operation of user data streams onto the downlink sub-channels and uplink multiple access by means of dividing OFDM subcarriers as sub-channels. The main issue of high-speed, single-wavelength upstream OFDMA-PON arises from optical beating interference noise. Because the sub-channels are allocated dynamically to multiple access users over same nominal wavelength, it generates the optical beating interference among upstream signals. In this paper, we proposed a novel scheme using self-homodyne balanced detection in the optical line terminal (OLT) to reduce OBI noise which is generated in the uplink transmission of OFDMA-PON system. When multiple OFDMA sub-channels over the same nominal wavelength are received at the same time in the proposed architecture, OBI noises can be removed using balanced detection. Using discrete multitone modulation (DMT) to generate real valued OFDM signals, the proposed technique is verified through experimental demonstration.

Performance Enhancement of Multichannel Gigabit Rate Bidirectional WDM-PON Using RSOA and Optimized Modulation Format

NASA Astrophysics Data System (ADS)

Parkash, Sooraj; Sharma, Anurag; Singh, Harsukhpreet

2016-09-01

This paper successfully demonstrates bidirectional wavelength division multiplexing passive optical network (WDM-PON) system for 32 channels, 0.8 nm (100 GHz) channels spacing with 3.5 GHz filter bandwidth. The system delivers 160 GB/s data rate and 80 GB/s data rate in downstream and upstream, respectively. The optical source for downstream data and upstream data is mode-locked laser at central office and reflective semiconductor optical amplifier (RSOA) at optical network unit. The maximum reach of designed system is 50 km without using any dispersion compensation scheme. This paper comprises comparison of series of modulation format in downstream and upstream such as SOLITON, NRZ, RZ, MANCHESTER, CSRZ and CRZ-DPSK and optimization of the performance of designed system. It has been observed that CRZ-DPSK/NRZ gives best performance in downstream and upstream transmission for designed system. The simulation work report of minimum BER is e-13 for CRZ-DPSK in downstream and e-16 for NRZ in upstream transmission in case of 32-channel bidirectional WDM-PON.

Multi-granularity Bandwidth Allocation for Large-Scale WDM/TDM PON

NASA Astrophysics Data System (ADS)

Gao, Ziyue; Gan, Chaoqin; Ni, Cuiping; Shi, Qiongling

2017-12-01

WDM (wavelength-division multiplexing)/TDM (time-division multiplexing) PON (passive optical network) is being viewed as a promising solution for delivering multiple services and applications, such as high-definition video, video conference and data traffic. Considering the real-time transmission, QoS (quality of services) requirements and differentiated services model, a multi-granularity dynamic bandwidth allocation (DBA) in both domains of wavelengths and time for large-scale hybrid WDM/TDM PON is proposed in this paper. The proposed scheme achieves load balance by using the bandwidth prediction. Based on the bandwidth prediction, the wavelength assignment can be realized fairly and effectively to satisfy the different demands of various classes. Specially, the allocation of residual bandwidth further augments the DBA and makes full use of bandwidth resources in the network. To further improve the network performance, two schemes named extending the cycle of one free wavelength (ECoFW) and large bandwidth shrinkage (LBS) are proposed, which can prevent transmission from interruption when the user employs more than one wavelength. The simulation results show the effectiveness of the proposed scheme.

Physical-enhanced secure strategy in an OFDM-PON.

PubMed

Zhang, Lijia; Xin, Xiangjun; Liu, Bo; Yu, Jianjun

2012-01-30

The physical layer of optical access network is vulnerable to various attacks. As the dramatic increase of users and network capacity, the issue of physical-layer security becomes more and more important. This paper proposes a physical-enhanced secure strategy for orthogonal frequency division multiplexing passive optical network (OFDM-PON) by employing frequency domain chaos scrambling. The Logistic map is adopted for the chaos mapping. The chaos scrambling strategy can dynamically allocate the scrambling matrices for different OFDM frames according to the initial condition, which enhance the confidentiality of the physical layer. A mathematical model of this secure system is derived firstly, which achieves a secure transmission at physical layer in OFDM-PON. The results from experimental implementation using Logistic mapped chaos scrambling are also given to further demonstrate the efficiency of this secure strategy. An 10.125 Gb/s 64QAM-OFDM data with Logistic mapped chaos scrambling are successfully transmitted over 25-km single mode fiber (SMF), and the experimental results show that proposed security scheme can protect the system from eavesdropper and attacker, while keep a good performance for the legal ONU.

Remote-seeded WDM-PON upgrade using linear semiconductor opticalamplifiers

NASA Astrophysics Data System (ADS)

Martínez, J. J.; Merayo, N.; Villafranca, A.; Garcés, I.

2013-05-01

In this work we have assessed the capacity of a linear (gain-clamped) semiconductor optical amplifier to enhance the budget of WDM PON network links for their evolution from FTTC to FTTH access. A wavelength-seeded network architecture has been considered, evaluating the performance improvement obtained by the use of an amplifier for the cases of link reach extension and optical splitting to reach end users. The evaluation measurements have shown that the extra budget is enough to compensate for the losses of a passive splitter up to atleast 1:16 division rate or to highly increment reach of the network.

Enhanced optical gain clamping for upstream packet based traffic on hybrid WDM/TDM-PON using fiber Bragg grating

NASA Astrophysics Data System (ADS)

Neto, B.; Klingler, A.; Reis, C.; Dionísio, R. P.; Nogueira, R. N.; Teixeira, A. L. J.; André, P. S.

2011-03-01

In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An improvement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 dB.

Reconfigurable WDM-PON empowered by a low-cost 8-channel directly modulated laser module

NASA Astrophysics Data System (ADS)

Zhang, Yi-ming; Liu, Yu; Zhang, Zhi-ke; Zhao, Ze-ping; Tian, Ye; Zhu, Ning-hua

2017-11-01

A 10 Gbit/s 16-km-long reconfigurable wavelength-division-multiplexing passive optical network (WDM-PON) is presented empowered by a low-cost multi-channel directly modulated laser (DML) module. Compared with the case using discrete devices in conventional scheme, the proposed DML module provides a cost-effective solution with reduced complexity. The clear eye diagram and the bit error rate ( BER) of less than 2×10-7 with a sensitivity of -7 dBm are obtained. Due to the special packaging design, the crosstalk between channels under condition of simultaneous operation can be negligible.

Measurement of characteristic parameters of 10 Gb/s bidirectional optical amplifier for XG-PON

NASA Astrophysics Data System (ADS)

Rakkammee, Suchaj; Boriboon, Budsara; Worasucheep, Duang-rudee; Wada, Naoya

2018-03-01

This research experimentally measured the characteristic parameters of 10 Gb/s bidirectional optical amplifier: (1) operating wavelength range, (2) small signal gain, (3) Polarization Dependent Loss (PDL), and (4) power consumption. Bidirectional amplifiers are the key component to extend coverage area as well as increase a number of users in Passive Optical Networks (PON). According to 10-Gigabit-capable PON or XG-PON standard, the downstream and upstream wavelengths are 1577 nm and 1270 nm respectively. Thus, our bidirectional amplifier consists of an Erbium Doped Fiber Amplifier (EDFA) and a Semiconductor Optical Amplifier (SOA) for downstream and upstream wavelength transmissions respectively. The operating wavelengths of EDFA and SOA are measured to be from 1570 nm to 1588 nm and 1263 nm to 1280 nm respectively. To measure gain, the input wavelengths of EDFA and SOA were fixed at 1577 nm and 1271 nm respectively, while their input powers were reduced by a variable optical attenuator. The small signal gain of EDFA is 22.5 dB at 0.15 Ampere pump current, whereas the small signal gain of SOA is 7.06 dB at 0.325 Ampere pump current. To measure PDL, which is a difference in output powers at various State of Polarization (SoP) of input signal, a polarization controller was inserted before amplifier to alter input SoP. The measured PDL of EDFA is insignificant with less than 0.1 dB. In contrast, the measured PDL of SOA is as large as 33 dB, indicating its strong polarization dependence. The total power consumptions were measured to be 1.5675 Watt.

Generalized Anxiety Disorder (GAD) and Comorbid Major Depression with GAD Are Characterized by Enhanced Nitro-oxidative Stress, Increased Lipid Peroxidation, and Lowered Lipid-Associated Antioxidant Defenses.

PubMed

Maes, Michael; Bonifacio, Kamila Landucci; Morelli, Nayara Rampazzo; Vargas, Heber Odebrecht; Moreira, Estefânia Gastaldello; St Stoyanov, Drozdstoy; Barbosa, Décio Sabbatini; Carvalho, André F; Nunes, Sandra Odebrecht Vargas

2018-05-07

Accumulating evidence shows that nitro-oxidative pathways play an important role in the pathophysiology of major depressive disorder (MDD) and bipolar disorder (BD) and maybe anxiety disorders. The current study aims to examine superoxide dismutase (SOD1), catalase, lipid hydroperoxides (LOOH), nitric oxide metabolites (NOx), advanced oxidation protein products (AOPP), malondialdehyde (MDA), glutathione (GSH), paraoxonase 1 (PON1), high-density lipoprotein cholesterol (HDL), and uric acid (UA) in participants with and without generalized anxiety disorder (GAD) co-occurring or not with BD, MDD, or tobacco use disorder. Z unit-weighted composite scores were computed as indices of nitro-oxidative stress driving lipid and protein oxidation. SOD1, LOOH, NOx, and uric acid were significantly higher and HDL and PON1 significantly lower in participants with GAD than in those without GAD. GAD was more adequately predicted by increased SOD + LOOH + NOx and lowered HDL + PON1 composite scores. Composite scores of nitro-oxidative stress coupled with aldehyde and AOPP production were significantly increased in participants with comorbid GAD + MDD as compared with all other study groups, namely MDD, GAD + BD, BD, GAD, and healthy controls. In conclusion, GAD is characterized by increased nitro-oxidative stress and lipid peroxidation and lowered lipid-associated antioxidant defenses, while increased uric acid levels in GAD may protect against aldehyde production and protein oxidation. This study suggests that increased nitro-oxidative stress and especially increased SOD1 activity, NO production, and lipid peroxidation as well as lowered HDL-cholesterol and PON1 activity could be novel drug targets for GAD especially when comorbid with MDD.

Increased noradrenaline levels in the rostral pons can be reversed by M1 antagonist in a rat model of post-traumatic stress disorder.

PubMed

Terzioğlu, Berna; Kaleli, Melisa; Aydın, Banu; Ketenci, Sema; Cabadak, Hülya; Gören, M Zafer

2013-08-01

The dysregulation of hypothalamic-pituitary-adrenal axis and noradrenergic, serotonergic and glutamatergic systems are thought to be involved in the pathophysiology of post-traumatic stress disorder. The effect of selective M1 muscarinic receptor antagonist, pirenzepine on anxiety indices was investigated by using elevated plus maze, following exposure to trauma reminder. Upon receiving the approval of ethics committee, Sprague-Dawley rats were exposed to dirty cat litter (trauma) for 10 min and 1 week later, the rats confronted to a trauma reminder (clean litter). The rats also received intraperitoneal pirenzepine (1 or 2 mg/kg/day) or saline for 8 days. Noradrenaline (NA) concentration in the rostral pons was analyzed by HPLC with electrochemical detection. The anxiety indices of the rats subjected to the trauma reminder were increased when compared to control rats (p < 0.05). Pirenzepine treatment in traumatized rats displayed similar anxiety indices of non-traumatized rats treated with physiological saline. Although freezing time was prolonged with pirenzepine in traumatized groups the change was not found statistically significant. The NA level was 1.5 ± 0.1 pg/mg in non-traumatized rats and increased to 2.4 ± 0.2 pg/mg in traumatized rats. Bonferroni post hoc test revealed that the NA content of the rostral pons of the traumatized rats treated with physiological saline was significantly higher than the content of other groups (p < 0.01). We conclude that NA content in the rostral pons increases in respect to confrontation to a trauma reminder which can be reversed by M1 antagonist pirenzepine indicating the roles of M1 receptors.

Paraoxonase 1 (Q192R) gene polymorphism, coronary heart disease and the risk of a new acute coronary event.

PubMed

Martínez-Quintana, Efrén; Rodríguez-González, Fayna; Medina-Gil, José María; Garay-Sánchez, Paloma; Tugores, Antonio

Paraoxonase 1 (PON1) plays a major role in the oxidation of low density lipoprotein and in the prevention of coronary atherogenesis. In this context, coding region polymorphisms of PON1 gene, responsible for the enzyme activity, has become of interest as a marker for atherogenesis. A study and follow-up was conducted on 529 patients with an acute coronary event in order to assess the association between the PON1 Q192R (rs662;A/G) polymorphism, the type of acute coronary syndrome, cardiovascular risk factors (arterial hypertension, diabetes mellitus, dyslipidaemia, and smoking), the extent and severity of coronary atherosclerosis, and the medium-term clinical follow-up. The QQ genotype was found in 245 (46.3%) patients, with 218 (41.2%) patients showing the QR genotype, and 66 (14.5%) patients had the RR genotype. No significant differences were found between the QQ and QR/RR genotypes as regards the clinical characteristics, the analytical data, and the angiographic variables. Similarly, Kaplan-Meier survival analysis showed no significant differences in presenting with a new acute coronary event (p=0.598), cardiac mortality (p=0.701), stent thrombosis (p=0.508), or stent re-stenosis (p=0.598) between QQ and QR/RR genotypes during the follow-up period (3.3±2.2 years). In patients with an acute coronary syndrome, the PON1 Q192R genotypes did not influence the risk of suffering a new acute coronary event during the medium-term follow-up. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Association between ethnicity and obesity with high-density lipoprotein (HDL) function and subclass distribution.

PubMed

Woudberg, Nicholas J; Goedecke, Julia H; Blackhurst, Dee; Frias, Miguel; James, Richard; Opie, Lionel H; Lecour, Sandrine

2016-05-11

Obesity and low high-density lipoprotein-cholesterol (HDL-C) levels are associated with cardiovascular risk. Surprisingly, despite a greater prevalence of obesity and lower HDL concentrations than white women, black South African women are relatively protected against ischaemic heart disease. We investigated whether this apparent discrepancy may be related to different HDL function and subclass distribution in black and white, normal-weight and obese South African women (n = 40). HDL functionality was assessed by measuring paraoxonase (PON) activity, platelet activating factor acetylhydrolase (PAF-AH) activity, Oxygen Radical Absorbance Capacity (ORAC) and quantification of the expression of vascular cell adhesion molecule in endothelial cells. PON-1 and PAF-AH expression was determined in isolated HDL and serum using Western blotting. Levels of large, intermediate and small HDL subclasses were measured using the Lipoprint® system. PON activity was lower in white compared to black women (0.49 ± 0.09 U/L vs 0.78 ± 0.10 U/L, p < 0.05), regardless of PON-1 protein levels. Obese black women had lower PAF-AH activity (9.34 ± 1.15 U/L vs 13.89 ± 1.21 U/L, p <0.05) and HDL-associated PAF-AH expression compared to obese white women. Compared to normal-weight women, obese women had lower large HDL, greater intermediate and small HDL; an effect that was more pronounced in white women than black women. There were no differences in antioxidant capacity or anti-inflammatory function across groups. Our data show that both obesity and ethnicity are associated with differences in HDL functionality, while obesity was associated with decreases in large HDL subclass distribution. Measuring HDL functionality and subclass may, therefore, be important factors to consider when assessing cardiovascular risk.

Chimeric proteins combining phosphatase and cellulose-binding activities: proof-of-concept and application in the hydrolysis of paraoxon.

PubMed

Gonçalves, Larissa M; Chaimovich, Hernan; Cuccovia, Iolanda M; Marana, Sandro R

2014-05-01

Phosphatases for organophosphate degradation and carbohydrate-binding domains (CBMs) have potential biotechnological applications. As a proof-of-concept, a soluble chimeric protein that combines acid phosphatase (AppA) from Escherichia coli and a CBM from Xanthomonas axonopodis pv. citri (AppA-CBM) was produced in E.coli. AppACBM adsorbed in microcrystalline cellulose Avicel PH101 catalyzed the hydrolysis of p-nitrophenyl phosphate (PNPP). The binding to microcrystalline cellulose displayed saturation behavior with an apparent binding constant (Kb) of 22 ± 5 mg and a maximum binding (Bmax) of 1.500 ± 0.001 enzyme units. Binding was highest at pH 2.5 and decreased above pH 6.5, as previously observed for family 2 CBMs. The Km values for PNPP of AppA-CBM and native AppA were identical (2.7 mM). To demonstrate that this strategy for protein engineering has practical applications and is largely functional, even for phosphatases exhibiting diverse folds, a chimeric protein combining human paraoxonase 1 (hPON1) and the CBM was produced. Both PON1-CBM and hPON1 had identical K_m values for paraoxon (1.3 mM). Additionally, hPON1 bound to microcrystalline cellulose with a Kb of 27 ± 3 mg, the same as that observed for AppA-CBM. These data show that the phosphatase domains are as functional in both of the chimeric proteins as they are in the native enzymes and that the CBM domain maintains the same cellulose affinity. Therefore, the engineering of chimeric proteins combining domains of phosphatases and CBMs is fully feasible, resulting in chimeric enzymes that exhibit potential for OP detoxification.

A decision tree for differentiating multiple system atrophy from Parkinson's disease using 3-T MR imaging.

PubMed

Nair, Shalini Rajandran; Tan, Li Kuo; Mohd Ramli, Norlisah; Lim, Shen Yang; Rahmat, Kartini; Mohd Nor, Hazman

2013-06-01

To develop a decision tree based on standard magnetic resonance imaging (MRI) and diffusion tensor imaging to differentiate multiple system atrophy (MSA) from Parkinson's disease (PD). 3-T brain MRI and DTI (diffusion tensor imaging) were performed on 26 PD and 13 MSA patients. Regions of interest (ROIs) were the putamen, substantia nigra, pons, middle cerebellar peduncles (MCP) and cerebellum. Linear, volumetry and DTI (fractional anisotropy and mean diffusivity) were measured. A three-node decision tree was formulated, with design goals being 100 % specificity at node 1, 100 % sensitivity at node 2 and highest combined sensitivity and specificity at node 3. Nine parameters (mean width, fractional anisotropy (FA) and mean diffusivity (MD) of MCP; anteroposterior diameter of pons; cerebellar FA and volume; pons and mean putamen volume; mean FA substantia nigra compacta-rostral) showed statistically significant (P < 0.05) differences between MSA and PD with mean MCP width, anteroposterior diameter of pons and mean FA MCP chosen for the decision tree. Threshold values were 14.6 mm, 21.8 mm and 0.55, respectively. Overall performance of the decision tree was 92 % sensitivity, 96 % specificity, 92 % PPV and 96 % NPV. Twelve out of 13 MSA patients were accurately classified. Formation of the decision tree using these parameters was both descriptive and predictive in differentiating between MSA and PD. • Parkinson's disease and multiple system atrophy can be distinguished on MR imaging. • Combined conventional MRI and diffusion tensor imaging improves the accuracy of diagnosis. • A decision tree is descriptive and predictive in differentiating between clinical entities. • A decision tree can reliably differentiate Parkinson's disease from multiple system atrophy.

Increased nitrogen export from eastern North America to the Atlantic Ocean due to climatic and anthropogenic changes during 1901-2008

NASA Astrophysics Data System (ADS)

Yang, Qichun; Tian, Hanqin; Friedrichs, Marjorie A. M.; Hopkinson, Charles S.; Lu, Chaoqun; Najjar, Raymond G.

2015-06-01

We used a process-based land model, Dynamic Land Ecosystem Model 2.0, to examine how climatic and anthropogenic changes affected riverine fluxes of ammonium (NH4+), nitrate (NO3-), dissolved organic nitrogen (DON), and particulate organic nitrogen (PON) from eastern North America, especially the drainage areas of the Gulf of Maine (GOM), Mid-Atlantic Bight (MAB), and South Atlantic Bight (SAB) during 1901-2008. Model simulations indicated that annual fluxes of NH4+, NO3-, DON, and PON from the study area during 1980-2008 were 0.019 ± 0.003 (mean ± 1 standard deviation) Tg N yr-1, 0.18 ± 0.035 Tg N yr-1, 0.10 ± 0.016 Tg N yr-1, and 0.043 ± 0.008 Tg N yr-1, respectively. NH4+, NO3-, and DON exports increased while PON export decreased from 1901 to 2008. Nitrogen export demonstrated substantial spatial variability across the study area. Increased NH4+ export mainly occurred around major cities in the MAB. NO3- export increased in most parts of the MAB but decreased in parts of the GOM. Enhanced DON export was mainly distributed in the GOM and the SAB. PON export increased in coastal areas of the SAB and northern parts of the GOM but decreased in the Piedmont areas and the eastern parts of the MAB. Climate was the primary reason for interannual variability in nitrogen export; fertilizer use and nitrogen deposition tended to enhance the export of all nitrogen species; livestock farming and sewage discharge were also responsible for the increases in NH4+ and NO3- fluxes; and land cover change (especially reforestation of former agricultural land) reduced the export of the four nitrogen species.

The gene-treatment interaction of paraoxonase-1 gene polymorphism and statin therapy on insulin secretion in Japanese patients with type 2 diabetes: Fukuoka diabetes registry.

PubMed

Sumi, Akiko; Nakamura, Udai; Iwase, Masanori; Fujii, Hiroki; Ohkuma, Toshiaki; Ide, Hitoshi; Jodai-Kitamura, Tamaki; Komorita, Yuji; Yoshinari, Masahito; Hirakawa, Yoichiro; Hirano, Atsushi; Kubo, Michiaki; Kitazono, Takanari

2017-12-12

Although statins deteriorate glucose metabolism, their glucose-lowering effects have emerged in some situations. Here, we assessed whether these effects are a consequence of statins' interaction with paraoxonase (PON)1 enzyme polymorphism. Adult Japanese type 2 diabetes patients (n = 3798) were enrolled in a cross-sectional study. We used Q192R polymorphism of the PON1 gene as a representative single-nucleotide polymorphism and focused on the effects of the wild-type Q allele, in an additive manner. For patients with and without statin therapy, the associations of this allele with fasting plasma glucose (FPG), HbA 1c , C-peptide, HOMA2-%β, and HOMA2-IR were investigated separately using a linear regression model, and were compared between groups by testing interactions. Sensitivity analyses were performed using propensity score to further control the imbalance of characteristics between groups. Among patients with statin therapy, there were linear associations of the number of Q alleles with decreased FPG and HbA 1c , and with increased serum C peptide and HOMA2-%β (all P < 0.01 for trends), while such associations were not observed among those without statin therapy. These differences were statistically significant only for serum C peptide and HOMA2-%β (P < 0.01 for interactions). These associations remained significant after multiple explanatory variable adjustment. Sensitivity analyses using propensity score showed broad consistency of these associations. Patients with the Q allele of the PON1 Q192R polymorphism who were treated with statins exhibited improvement in glucose metabolism, especially in insulin secretion, suggesting the importance of genotyping PON1 Q192R to identify those who could benefit from statin therapy.

Comparison of serum oxidant and antioxidant parameters in familial Mediterranean fever patients (FMF) with attack free period.

PubMed

Şahin, Ali; Erten, Şükran; Altunoğlu, Alpaslan; Işıkoğlu, Semra; Neşelioğlu, Salim; Ergin, Merve; Atalay, Hacı Veli; Erel, Özcan

2014-01-01

Familial Mediterranean fever (FMF) is an autoinflammatory, autosomal recessive, inherited disease characterized by recurrent self-limiting attacks of serosal surfaces. The imbalance of oxidants/antioxidants may play a role in such attacks. In this study, we aimed to evaluate the relationship between serum paraoxonase (PON1) activity, PON1 phenotype, and other parameters in patients with FMF and healthy controls. A total of 120 FMF patients with an attack-free period (AFP) and 65 healthy subjects were included in this study. The serum PON1 activity, stimulated paraoxonase (SPON) activity, PON1 phenotype (representing Q192R polymorphism; QQ, QR, RR), arylesterase activity, total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), advanced oxidative protein products (AOPP), total thiols (TTL), and ischemia-modified albumin (IMA) and cystatin-c (CYS-C) levels were measured. For the QQ phenotype, the median TTL and AOPP levels of the control group were 264.50 (57.75) mol/L and 21.26 (21.17) mmol/L, respectively, whereas the median TTL, AOPP levels of the patients were 309.00 (47.00) mol/L and 12.98 (6.96) mmol/L, respectively. There was a statistically significant difference between the patients and controls with the QQ phenotype in terms of TTL and AOPP (p< 0.001 and p= 0.004, respectively). However, there were no statistically significant differences between the QQ and QR+RR phenotypes with respect to TAC, TOS, OSI, or the other parameters. The FMF patients with AFP had higher TTL and lower AOPP levels than the controls. However, other oxidant and antioxidant parameters were similar among the patients during AFP and the controls.

Q192R polymorphism in the PON1 gene and familial hypercholesterolemia in a Saudi population.

PubMed

Alharbi, Khalid Khalaf; Alnbaheen, May Salem; Alharbi, Fawiziah Khalaf; Hasanato, Rana M; Khan, Imran Ali

2017-01-01

Familial hypercholesterolemia (FH) is an autosomal dominant condition characterized by abnormal levels of low-density lipoprotein (LDL) in the blood. FH is a risk factor for atherosclerosis and cardiovascular disease. The relationship between the paraoxonase 1 (PON1) gene, atherosclerosis and coronary artery disease has not been studied in Saudi patients. To investigate the genetic associations of the Q192R polymorphism in the PON1 gene with FH in Saudi patients. Case-control study. Tertiary care center, Riyadh. Two hundred Saudi patients were enrolled in this study, including 100 patients with FH and 100 healthy controls, during the period from January 2012 to March 2013. Serum was separated from coagulated blood (3 mL) and used for analysis of lipid profiles. Genomic DNA was isolated from anticoagulant-treated blood (2 mL). Genotyping for the Q192R polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism analysis, followed by 3% agarose gel electrophoresis. The strength of association between the Q192R polymorphism and FH in the Saudi population. We confirmed that QR versus QQ (odds ratio [OR]: 1.55; 95% confidence interval [CI]: 1.05-3.43; P=.03), QR+RR versus QQ (OR: 1.98; 95% CI: 1.13-3.49; P=.01), and R versus Q (OR: 1.68; 95% CI: 1.09- 2.59; P=.01) in the Q192R polymorphism were associated with FH in the Saudi population. In conclusion, the Q192R polymorphism in the PON1 gene is associated with FH in the Saudi population. Our results confirmed that the R allele, QR, and dominant model genotypes were associated with FH. Only a single variant (Q192R) was analyzed, and the medical and family histories of the patients were not known.

Progressive retinal atrophy in the Polski Owczarek Nizinny dog: a clinical and genetic study.

PubMed

Svensson, Marika; Olsén, Lena; Winkler, Paige A; Petersen-Jones, Simon M; Bergström, Tomas; Garncarz, Yacek; Narfström, Kristina

2016-05-01

To describe ophthalmic, functional, structural, and genetical characteristics of progressive retinal atrophy (PRA) in the polski owczarek nizinny (PON) breed of dog. Client-owned PON dogs (n = 82) from Sweden. Routine examination for presumed inherited eye disease was performed in all dogs. Bilateral full-field electroretinography (ERG) was performed in 11 affected and 4 control dogs. Eyes from one affected dog were studied with light microscopy. DNA samples from 34 Swedish and 30 PON dogs collected by Michigan State University (MSU) were tested for the mutations causing the rcd4 and prcd forms of PRA. Sixteen of the eighty-two Swedish dogs were diagnosed with PRA. Slight vascular attenuation, first seen at 4.5 years of age, preceded changes in tapetal reflectivity. The initial ERG changes in affected dogs showed markedly diminished rod responses, while cone responses were barely affected. Eventually, cone responses were also reduced. Retinal morphology showed approximately a 50% reduction of photoreceptor nuclei in the outer nuclear layer. Fourteen of fifteen PRA-affected Swedish dogs and eighteen of twenty of the MSU PRA-affected dogs tested genetically were positive for the rcd4 mutation. All tested dogs were negative for the mutation causing prcd-PRA. PRA of PON dogs is a late-onset degenerative disease with slow progression. There is early loss of rod function, while the cone system deteriorates later. The rcd4 mutation in the C2ORF71 gene was associated with the majority of the PRA cases tested. The possibility of additional forms of PRA in the breed cannot be excluded. © 2015 American College of Veterinary Ophthalmologists.

Caffeic acid phenethyl ester protects kidneys against acetylsalicylic acid toxicity in rats.

PubMed

Bozkurt, Yasar; Bozkurt, Mehtap; Turkçu, Gul; Sancaktutar, Ahmet Ali; Soylemez, Haluk; Penbegul, Necmettin; Atar, Murat; Bodakcı, Mehmet Nuri; Hatipoglu, Namık Kemal; Yuksel, Hatice; Kıbrıslı, Erkan; Yavuz, Celal

2012-01-01

The aim of this study was to investigate the protective effect of caffeic acid phenethyl ester (CAPE) on acetylsalicylic acid (ASA)-induced renal damage in rats. A total of 40 rats were randomly divided into five groups, with eight rats in each group-group 1: control, not receiving any medication; group 2: ASA (50 mg/kg/day); group 3: ASA (50 mg/kg/day) + CAPE (20 μg/kg/day); group 4: ASA (100 mg/kg/day); and group 5: ASA (100 mg/kg/day) + CAPE (20 μg/kg/day). ASA and CAPE were given via orogastric gavage for 5 days. The total oxidant status (TOS), total antioxidant capacity (TAC), and paraoxonase-1 (PON-1) activity of the blood samples and kidney tissues were determined. Histopathological examinations of the kidneys were performed using light microscopic methods. The TOS level in the serum of rats and kidney tissues given ASA (groups 2 and 4) significantly increased, but the levels of TAC and PON-1 in these tissues significantly decreased in group 4 when compared with the control rats (p < 0.05). The levels of TAC and PON-1 in the kidney tissues increased and the levels of TOS decreased in the CAPE treatment groups (groups 3 and 5) when compared with the rats in the no CAPE treatment groups (groups 2 and 4). The PON-1, TAC, and TOS values reverted to normal levels in group 5 when compared to group 4 (p < 0.05). These results were supported by histopathological observation. Oxidative stress plays an important role in ASA-induced nephrotoxicity, and CAPE may protect against ASA-induced nephrotoxicity in rats.

WDM/TDM PON experiments using the AWG free spectral range periodicity to transmit unicast and multicast data

NASA Astrophysics Data System (ADS)

Bock, Carlos; Prat, Josep

2005-04-01

A hybrid WDM/TDM PON architecture implemented by means of two cascaded Arrayed Waveguide Gratings (AWG) is presented. Using the Free Spectral Range (FSR) periodicity of AWGs we transmit unicast and multicast traffic on different wavelengths to each Optical Network Unit (ONU). The OLT is equipped with two laser stacks, a tunable one for unicast transmission and a fixed one for multicast transmission. We propose the ONU to be reflective in order to avoid any light source at the Costumer Premises Equipment (CPE). Optical transmission tests demonstrate correct transmission at 2.5 Gbps up to 30 km.

Suppression of pattern dependence in 10 Gbps upstream transmission of WDM-PON with RSOA-based ONUs

NASA Astrophysics Data System (ADS)

Zhang, Min; Wang, Danshi; Cao, Zhihui; Chen, Xue; Huang, Shanguo

2013-11-01

The finite gain recovery time of the reflective semiconductor optical amplifier (RSOA) causes distortion and pattern dependence at high bit rates in colorless optical network units (ONUs) of WDM passive optical network (WDN-PON). We propose and demonstrate a scheme of upstream transmission of 10 Gbps NRZ signals directly modulated via a RSOA in a 25 km single fiber, where we use a fiber Bragg grating (FBG) as an offset filter to suppress the pattern dependence and improve the RSOA modulation bandwidth. Both experimental and simulation results are provided, which are useful results for designing cost-effective colorless transceivers.

Self-homodyne optical OFDM for broadband WDM-PONs with crosstalk-free remodulation and enhanced tolerance to Rayleigh noise

NASA Astrophysics Data System (ADS)

Lyu, WeiChao; Wang, Andong; Xie, Dequan; Zhu, Long; Guan, Xun; Wang, Jian; Xu, Jing

2018-05-01

We propose a novel architecture for wavelength-division-multiplexed passive optical network (WDM-PON) that can simultaneously circumvent both remodulation crosstalk and Rayleigh noise, based on self-homodyne detection and optical orthogonal frequency-division multiplexing (OFDM) remodulation. The proposed self-homodyne detection at optical network unit (ONU) requires neither frequency offset compensation nor phase noise compensation, and thus can significantly reduce system complexity and power consumption. Bidirectional transmission of 12.5 Gb/s down- and up-stream signals, via single 25 km single-mode fiber without dispersion compensation, is demonstrated in a proof-of-concept experiment.

In-service communication channel sensing based on reflectometry for TWDM-PON systems

NASA Astrophysics Data System (ADS)

Iida, Daisuke; Kuwano, Shigeru; Terada, Jun

2014-05-01

Many base stations are accommodated in TWDM-PON based mobile backhaul and fronthaul networks for future radio access, and failed connections in an optical network unit (ONU) wavelength channel severely degrade system performance. A cost effective in-service ONU wavelength channel monitor is essential to ensure proper system operation without failed connections. To address this issue we propose a reflectometry-based remote sensing method that provides wavelength channel information with the optical line terminal (OLT)-ONU distance. The method realizes real-time monitoring of ONU wavelength channels without signal quality degradation. Experimental results show it achieves wavelength channel distinction with high distance resolution.

Impact of PON deployment on metro networks

NASA Astrophysics Data System (ADS)

Poirrier, Julien; Herviou, Fabrice; Barboule, Hélène; Moignard, Maryse

2009-01-01

FTTH or FTTC, depending on countries and areas, will be the key technology for operators to differentiate themselves from competitors and win market share. Such a disruptive evolution of the access network should be supported by a significant re-design of the higher network layers. In the present paper, the required features of these new WDM networks are presented. Capacity and cost are the two obvious drivers. But versatility will be crucial to cope with an uncertain context (tedious prediction of traffic, regulation and services) and with very diverse population densities. Finally we also address how PON could benefit from mature WDM technologies to ease the global network design.

Large optical 3D MEMS switches in access networks

NASA Astrophysics Data System (ADS)

Madamopoulos, Nicholas; Kaman, Volkan; Yuan, Shifu; Jerphagnon, Olivier; Helkey, Roger; Bowers, John E.

2007-09-01

Interest is high among residential customers and businesses for advanced, broadband services such as fast Internet access, electronic commerce, video-on-demand, digital broadcasting, teleconferencing and telemedicine. In order to satisfy such growing demand of end-customers, access technologies such as fiber-to-the-home/building (FTTH/B) are increasingly being deployed. Carriers can reduce maintenance costs, minimize technology obsolescence and introduce new services easily by reducing active elements in the fiber access network. However, having a passive optical network (PON) also introduces operational and maintenance challenges. Increased diagnostic monitoring capability of the network becomes a necessity as more and more fibers are provisioned to deliver services to the end-customers. This paper demonstrates the clear advantages that large 3D optical MEMS switches offer in solving these access network problems. The advantages in preventative maintenance, remote monitoring, test and diagnostic capability are highlighted. The low optical insertion loss for all switch optical connections of the switch enables the monitoring, grooming and serving of a large number of PON lines and customers. Furthermore, the 3D MEMS switch is transparent to optical wavelengths and data formats, thus making it easy to incorporate future upgrades, such higher bit rates or DWDM overlay to a PON.

A developmental classification of malformations of the brainstem.

PubMed

Barkovich, A James; Millen, Kathleen J; Dobyns, William B

2007-12-01

With advances in imaging and genetics, malformations of the brainstem are being more commonly identified. We describe and classify brainstem anomalies in 138 patients ascertained over a period of 10 years Magnetic resonance imaging studies and, where available, clinical records of the patients were retrospectively reviewed. Malformations were segregated according to magnetic resonance findings and classified when possible by embryological mechanisms The most common location for anomalies was the pons, which was involved in 114 patients. The midbrain was involved in 45 patients, whereas the medulla was involved in 14. In 53 patients, more than 1 region was affected (all 3 regions in 6 patients, midbrain and pons in 39, and medulla and pons in 8). The malformations were divided into four groups: (1) malformations with abnormal brainstem segmentation, (2) malformations with segmental hypoplasia, (3) postsegmentation malformations, and (4) malformations associated with abnormal cortical organization The malformations of the brainstem identified in this study were diverse and complex. This proposed classification organizes them into groupings based on known genetics and embryological events. Use of this system will help clinicians and scientists to better understand these disorders and, ultimately, to better counsel families of affected patients.

Energy efficiency evaluation of tree-topology 10 gigabit ethernet passive optical network and ring-topology time- and wavelength-division-multiplexed passive optical network

NASA Astrophysics Data System (ADS)

Song, Jingjing; Yang, Chuanchuan; Zhang, Qingxiang; Ma, Zhuang; Huang, Xingang; Geng, Dan; Wang, Ziyu

2015-09-01

Higher capacity and larger scales have always been the top targets for the evolution of optical access networks, driven by the ever-increasing demand from the end users. One thing that started to attract wide attention not long ago, but with at least equal importance as capacity and scale, is energy efficiency, a metric essential nowadays as human beings are confronted with severe environmental issues like global warming, air pollution, and so on. Here, different from the conventional energy consumption analysis of tree-topology networks, we propose an effective energy consumption calculation method to compare the energy efficiency of the tree-topology 10 gigabit ethernet passive optical network (10G-EPON) and ring-topology time- and wavelength-division-multiplexed passive optical network (TWDM-PON), two experimental networks deployed in China. Numerical results show that the ring-topology TWDM-PON networks with 2, 4, 8, and 16 wavelengths are more energy efficient than the tree-topology 10G-EPON, although 10G-EPON consumes less energy. Also, TWDM-PON with four wavelengths is the most energy-efficient network candidate and saves 58.7% more energy than 10G-EPON when fully loaded.

A Systematic Scheme for Multiple Access in Ethernet Passive Optical Access Networks

NASA Astrophysics Data System (ADS)

Ma, Maode; Zhu, Yongqing; Hiang Cheng, Tee

2005-11-01

While backbone networks have experienced substantial changes in the last decade, access networks have not changed much. Recently, passive optical networks (PONs) seem to be ready for commercial deployment as access networks, due to the maturity of a number of enabling technologies. Among the PON technologies, Ethernet PON (EPON) standardized by the IEEE 802.3ah Ethernet in the First Mile (EFM) Task Force is the most attractive one because of its high speed, low cost, familiarity, interoperability, and low overhead. In this paper, we consider the issue of upstream channel sharing in the EPONs. We propose a novel multiple-access control scheme to provide bandwidth-guaranteed service for high-demand customers, while providing best effort service to low-demand customers according to the service level agreement (SLA). The analytical and simulation results prove that the proposed scheme performs best in what it is designed to do compared to another well-known scheme that has not considered providing differentiated services. With business customers preferring premium services with guaranteed bandwidth and residential users preferring low-cost best effort services, our scheme could benefit both groups of subscribers, as well as the operators.

Integrated coding-aware intra-ONU scheduling for passive optical networks with inter-ONU traffic

NASA Astrophysics Data System (ADS)

Li, Yan; Dai, Shifang; Wu, Weiwei

2016-12-01

Recently, with the soaring of traffic among optical network units (ONUs), network coding (NC) is becoming an appealing technique for improving the performance of passive optical networks (PONs) with such inter-ONU traffic. However, in the existed NC-based PONs, NC can only be implemented by buffering inter-ONU traffic at the optical line terminal (OLT) to wait for the establishment of coding condition, such passive uncertain waiting severely limits the effect of NC technique. In this paper, we will study integrated coding-aware intra-ONU scheduling in which the scheduling of inter-ONU traffic within each ONU will be undertaken by the OLT to actively facilitate the forming of coding inter-ONU traffic based on the global inter-ONU traffic distribution, and then the performance of PONs with inter-ONU traffic can be significantly improved. We firstly design two report message patterns and an inter-ONU traffic transmission framework as the basis for the integrated coding-aware intra-ONU scheduling. Three specific scheduling strategies are then proposed for adapting diverse global inter-ONU traffic distributions. The effectiveness of the work is finally evaluated by both theoretical analysis and simulations.

Combined utilization of partial-response coding and equalization for high-speed WDM-PON with centralized lightwaves.

PubMed

Guo, Qi; Tran, An V

2012-12-17

In this paper, we investigate the transmission impairments in a high-speed single-feeder wavelength-division-multiplexed passive optical network (WDM-PON) employing low-bandwidth upstream transmitter. A 1-GHz reflective semiconductor optical amplifier (RSOA) is operated at the rates of 10 Gb/s and 20 Gb/s in the proposed WDM-PON. Since the system performance is seriously limited by its uplink in both capacity and reach owing to inter-symbol interference and reflection noise, we present a novel technique with simultaneous capability of spectral efficiency enhancement and transmission distance extension in the uplink via coding and equalization that exploit the principles of partial-response (PR) signal. It is experimentally demonstrated that the proposed system supports the delivery of 10 Gb/s and 20 Gb/s upstream signals over 75-km and 25-km bidirectional fiber, respectively. The configuration of PR equalizer is optimized for its best performance-complexity trade-off. The reflection tolerance of 10 Gb/s and 20 Gb/s channels is improved by 8 dB and 6 dB, respectively, with PR coding. The proposed cost-effective signal processing scheme has great potential for the next-generation access networks.

A metro-access integrated network with all-optical virtual private network function using DPSK/ASK modulation format

NASA Astrophysics Data System (ADS)

Tian, Yue; Leng, Lufeng; Su, Yikai

2008-11-01

All-optical virtual private network (VPN), which offers dedicated optical channels to connect users within a VPN group, is considered a promising approach to efficient internetworking with low latency and enhanced security implemented in the physical layer. On the other hand, time-division multiplexed (TDM) / wavelength-division multiplexed (WDM) network architecture based on a feeder-ring with access-tree topology, is considered a pragmatic migration scenario from current TDM-PONs to future WDM-PONs and a potential convergence scheme for access and metropolitan networks, due to its efficiently shared hardware and bandwidth resources. All-optical VPN internetworking in such a metro-access integrated structure is expected to cover a wider service area and therefore is highly desirable. In this paper, we present a TDM/WDM metro-access integrated network supporting all-optical VPN internetworking among ONUs in different sub- PONs based on orthogonal differential-phase-shift keying (DPSK) / amplitude-shift keying (ASK) modulation format. In each ONU, no laser but a single Mach-Zehnder modulator (MZM) is needed for the upstream and VPN signal generation, which is cost-effective. Experiments and simulations are performed to verify its feasibility as a potential solution to the future access service.

Effects of Controlled Breathing, With or Without Aromatherapy, in the Treatment of Postoperative Nausea.

PubMed

Cronin, Sherill Nones; Odom-Forren, Jan; Roberts, Holli; Thomas, Melissa; Williams, Sandy; Wright, Margaret Imelda

2015-10-01

The purpose of this study was to compare the effectiveness of controlled breathing (CB), with and without aromatherapy (isopropyl alcohol [IPA]), in the treatment of postoperative nausea (PON) in adult females undergoing elective outpatient laparoscopic procedures. A prospective randomized two-group quasi-experimental design was used. A convenience sample was used. Patients were consented and assigned to either a control (CB) or treatment (IPA) group. Symptomatic patients rated nausea severity before and at 2 and 5 minutes after receiving either CB or CB with IPA. Complete data for one episode of nausea were obtained on 82 patients (41 in each group). Results showed that although nausea severity decreased significantly over time, there was no significant difference in PON treatment effectiveness between the two groups, nor was there a difference in requests for rescue medications. Patients who experience PON should be encouraged to take slow deep breaths as an initial response to symptoms. This approach has no side effects or costs and could also aid the patient to self-manage symptoms after discharge. Copyright © 2015 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Aronia melanocarpa Treatment and Antioxidant Status in Selected Tissues in Wistar Rats

PubMed Central

Krośniak, Mirosław; Sanocka, Ilona; Bartoń, Henryk; Hebda, Tomasz; Francik, Sławomir

2014-01-01

Aronia juice is considered to be a source of compounds with high antioxidative potential. We conducted a study on the impact of compounds in the Aronia juice on oxidative stress in plasma and brain tissues. The influence of Aronia juice on oxidative stress parameters was tested with the use of a model with a high content of fructose and nonsaturated fats. Therefore, the activity of enzymatic (catalase, CAT, and paraoxonase, PON) and nonenzymatic (thiol groups, SH, and protein carbonyl groups, PCG) oxidative stress markers, which indicate changes in the carbohydrate and protein profiles, was marked in brain tissue homogenates. Adding Aronia caused statistically significant increase in the CAT activity in plasma in all tested diets, while the PON activity showed a statistically significant increase only in case of high fat diet. In animals fed with Aronia juice supplemented with carbohydrates or fat, statistically significant increase in the PON activity and the decrease in the CAT activity in brain tissue were observed. In case of the high fat diet, an increase in the number of SH groups and a decrease in the number of PCG groups in brain tissue were observed. PMID:25057488

Aronia melanocarpa treatment and antioxidant status in selected tissues in Wistar rats.

PubMed

Francik, Renata; Krośniak, Mirosław; Sanocka, Ilona; Bartoń, Henryk; Hebda, Tomasz; Francik, Sławomir

2014-01-01

Aronia juice is considered to be a source of compounds with high antioxidative potential. We conducted a study on the impact of compounds in the Aronia juice on oxidative stress in plasma and brain tissues. The influence of Aronia juice on oxidative stress parameters was tested with the use of a model with a high content of fructose and nonsaturated fats. Therefore, the activity of enzymatic (catalase, CAT, and paraoxonase, PON) and nonenzymatic (thiol groups, SH, and protein carbonyl groups, PCG) oxidative stress markers, which indicate changes in the carbohydrate and protein profiles, was marked in brain tissue homogenates. Adding Aronia caused statistically significant increase in the CAT activity in plasma in all tested diets, while the PON activity showed a statistically significant increase only in case of high fat diet. In animals fed with Aronia juice supplemented with carbohydrates or fat, statistically significant increase in the PON activity and the decrease in the CAT activity in brain tissue were observed. In case of the high fat diet, an increase in the number of SH groups and a decrease in the number of PCG groups in brain tissue were observed.

Comparison of captopril and enalapril to study the role of the sulfhydryl-group in improvement of endothelial dysfunction with ACE inhibitors in high dieted methionine mice.

PubMed

Liu, Yu-Hui; Liu, Li-Ying; Wu, Jin-Xiang; Chen, Shuang-Xiu; Sun, Yin-Xue

2006-01-01

To examine the role of sulfhydryl (-SH) group in improvement of endothelial dysfunction with angiotensin-converting enzyme (ACE) inhibitors in experimental high dose of methionine dieted rats. We compared the effects of Captopril (an ACE inhibitor with -SH group), enalapril (an ACE-inhibitor without -SH group), N-acetylcysteine (only -SH group not ACE inhibitor) on endothelial dysfunction injured by methionine-induced hyperhomocysteinemia (HHcy) in rats. Male Sprague-Dawley rats were divided randomly into seven groups: control group, L-methionine group, low dose Captopril (15 mg/kg), middle dose Captopril (30 mg/kg), high dose Captopril (45 mg/kg), enalapril (20 mg/kg), N-acetylcysteine (200 mg/kg); control group were intragastric gavaged by water and others groups were intragastric gavaged by L-methionine and drugs in water one time every day. Acetylcholine (ACh)-induced endothelium-dependent relaxation (EDR), sodium nitroprusside (SNP)-induced endothelium-independent relaxation of aortic rings were examined. Paraoxonase1 (PON1) and ACE activity, malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD) in serum were analyzed. It was found that a single intragastric gavage by L-methionine resulted in inhibition of endothelium-dependent relaxation, markedly increased the serum level of malondialdehyde and decreased the activity of PON1 and SOD, similarly decreased the level of NO in the serum; but had no effects on endothelium-independent relaxation and angiotensin-converting enzyme activity compared with the control group. Given the treatment with three doses of Captopril (15 approximately 45 mg/kg) markedly attenuated inhibition of vasodilator responses to ACh, and eliminated the increased level of malondialdehyde, the decreased level of NO, activity of PON1 and SOD in serum by single intragastric gavaged L-methionine. However, there were some significant differences among Captopril (30 mg/kg or 45 mg/kg), enalapril (20 mg/kg), and N-acetylcysteine particular in the activity of PON1 and ACE. These results suggested that Captopril can protect the vascular endothelium against the damages induced by L-methionine in rats, and the beneficial effects of Captopril may be related to attenuating the decrease in PON1 activity and NO levels. Furthermore, this protective effect may be concerned with the sulfhydryl group.

Insights into nutrient assimilation and export in naturally iron-fertilized waters of the Southern Ocean from nitrogen, carbon and oxygen isotopes

NASA Astrophysics Data System (ADS)

Trull, Thomas W.; Davies, Diana; Casciotti, Karen

2008-03-01

The KErguelen Ocean and Plateau compared Study (KEOPS) documented enhanced iron input and phytoplankton biomass over the deep Kerguelen plateau in comparison to surrounding high-nutrient low-chlorophyll (HNLC) waters in late summer 2005. We examined the influence of this iron on nitrogen and carbon metabolism by the microbial food-web, by comparing samples from on-plateau and off-plateau. Suspended particulate organic carbon (POC) was ˜5 times more abundant on-plateau and exhibited greater POC/PON (˜6.5 vs. ˜5.5), δ13C-POC (˜-21.5 vs. ˜-24.5‰) and δ15N-PON (˜+2 vs. ˜0‰) than off-plateau. These differences arose in part from changes in ecosystem structure as demonstrated by size-fractionation (1, 5, 20, 55, 210, and 335-μm filters in series), which revealed large isotopic variations with size ( δ13C-POC ranged from -28 to -19‰ and δ15N-PON from -3 to +5‰) and greater abundances of 13C- and 15N-enriched large phytoplankton over the plateau. The 13C enrichment in POC reflected faster growth rates and greater draw-down of dissolved inorganic carbon over the plateau. Quantitative comparison to the δ15N of dissolved nitrate indicates that the δ15N-PON enrichment derived from increased assimilation of nitrate, corresponding to new production f-ratios of 0.7-0.9 on-plateau vs. 0.4-0.6 off-plateau. Results from a sparse set of free-drifting sediment trap samples suggest control of export by zooplankton grazing. The 15N and 18O enrichments in dissolved nitrate exhibited a 1:1 correlation, indicating that phytoplankton assimilation controls nitrate availability and only a relatively small amount of nitrate was regenerated by nitrification. The δ15N-NO 3 values yield indistinguishable isotopic fractionation factors on and off the plateau ( 15ɛ of 4-5‰). This suggests that variations in iron availability may not bias the interpretation of paleo-environmental 15N records, and leaves intact the view that higher sedimentary δ15N-PON values during the last glacial maximum indicate greater fractional nitrate depletion in the Southern Ocean.

Cost-effective TCM-based WDM-PON for highly asymmetric traffic conditions.

PubMed

Lee, Danbi; Kwon, Won-Bae; Chae, Chang-Joon; Park, Chang-Soo

2015-11-16

A time compression multiplexing (TCM)-based wavelength division multiplexing passive optical network (WDM-PON) using a reflective semiconductor optical amplifier (RSOA) is proposed, and its feasibility is experimentally demonstrated. In the proposed system, the RSOA pre-amplifies a 10 Gb/s downstream signal and modulates the RSOA output, wavelength-locked to the downstream signal, with a 1.25 Gb/s upstream signal simultaneously. The sensitivity of the downstream signal is improved by about 3 dB through the RSOA. The downstream and upstream signals have power penalties of about 0.1 dB and 1.1 dB, respectively, at bit error rates (BERs) of 10(-9) after 20 km transmission.

Optical power equalization for upstream traffic with injection-locked Fabry-Perot lasers in TDM-PON

NASA Astrophysics Data System (ADS)

Huang, Ting-Tsan; Sheu, Lih-Gen; Chi, Sien

2010-10-01

An optical power equalization of upstream traffic in time-division-multiplexed passive optical network (TDM-PON) based on injection-locked Fabry-Perot lasers has been experimentally investigated. The upstream transmitters with stable spectrum are achieved by using an external injection light source in the optical line terminal (OLT). The different upstream powers can be equalized by injection locking a Fabry-Perot laser diode (FP-LD) biased below threshold current in OLT. The dynamic upstream power range from - 8.5 to - 19.5 db m is reduced to a 1.6 dB maximal power variation, when the uplink signal is directly modulated at 1.25 Gb/s.

Seven-core multicore fiber transmissions for passive optical network.

PubMed

Zhu, B; Taunay, T F; Yan, M F; Fini, J M; Fishteyn, M; Monberg, E M; Dimarcello, F V

2010-05-24

We design and fabricate a novel multicore fiber (MCF), with seven cores arranged in a hexagonal array. The fiber properties of MCF including low crosstalk, attenuation and splice loss are described. A new tapered MCF connector (TMC), showing ultra-low crosstalk and losses, is also designed and fabricated for coupling the individual signals in-and-out of the MCF. We further propose a novel network configuration using parallel transmissions with the MCF and TMC for passive optical network (PON). To the best of our knowledge, we demonstrate the first bi-directional parallel transmissions of 1310 nm and 1490 nm signals over 11.3-km of seven-core MCF with 64-way splitter for PON.

Central Pontine and Extrapontine Myelinolysis: The Great Masquerader—An Autopsy Case Report

PubMed Central

Jacob, Sajish; Nikolic, Dejan; Gundogdu, Betul; Ong, Shirley

2014-01-01

Central pontine myelinolysis is a demyelinating disorder characterized by the loss of myelin in the center of the basis pontis usually caused by rapid correction of chronic hyponatremia. The clinical features vary depending on the extent of involvement. Demyelination can occur outside the pons as well and diagnosis can be challenging if both pontine and extrapontine areas are involved. We herein report a case of myelinolysis involving pons, lateral geniculate bodies, subependymal region, and spinal cord. To the best of our knowledge, this case represents the second case of spinal cord involvement in osmotic demyelination syndrome and the first case of involvement of thoracic region of spinal cord. PMID:24716023

Performance Analysis of Hybrid PON (WDM-TDM) with Equal and Unequal Channel Spacing

NASA Astrophysics Data System (ADS)

Sharma, Ramandeep; Dewra, Sanjeev; Rani, Aruna

2016-06-01

In this hybrid WDM-TDM PON has been evaluated and compared the downstream wavelengths with equal and unequal channel spacing at 5 Gbit/s per wavelength in the scenario of triple play services with 128 optical network units (ONUs). The triple play services: data, voice and video signals are transmitted up to 50 km distance having Q factor of 6.68 and BER of 3.64e-012 with unequal channel spacing and 45 km distance having Q factor of 6.33 and BER of 2.40e-011 with equal channel spacing in downstream direction. It has been observed that downstream wavelengths with unequal channel spacing provide better results than equal channel spacing.

CV2/CRMP5-antibody-related Paraneoplastic Optic Neuropathy Associated with Small-cell Lung Cancer.

PubMed

Nakajima, Masanori; Uchibori, Ayumi; Ogawa, Yuki; Miyazaki, Tai; Ichikawa, Yaeko; Kaneko, Kimihiko; Takahashi, Toshiyuki; Nakashima, Ichiro; Shiraishi, Hirokazu; Motomura, Masakatsu; Chiba, Atsuro

2018-06-01

A 61-year-old woman who had smoked for 41 years developed subacute dizziness, ataxic gait, opsoclonus, and right visual impairment. She had right optic disc swelling and optic nerve gadolinium enhancement on magnetic resonance imaging. She had small-cell lung cancer (SCLC), with CV2/collapsin response mediator protein (CRMP) 5 and HuD antibodies in her serum and cerebrospinal fluid. She was diagnosed with paraneoplastic optic neuropathy (PON) accompanied by paraneoplastic opsoclonus-ataxia syndrome. Her symptoms improved after removing the SCLC. Classical PON is rare in Japan. We recommend assaying for CV2/CRMP5 antibodies and searching for cancer in elderly patients with subacute painless visual impairment.

High resolution Li depth profiling of solid state Li ion battery by TERD technique with high energy light ions

NASA Astrophysics Data System (ADS)

Morita, K.; Tsuchiya, B.; Ohnishi, J.; Yamamoto, T.; Iriyama, Y.; Tsuchida, H.; Majima, T.; Suzuki, K.

2018-07-01

Li depth profiles in Au/Si/LiPON/LCO/Au (LCO = LiCoO2, LiPON = Li3.3PO3.8N0.2) thin films battery under charging condition, prepared on self-supporting Al substrate, have been in situ measured by means of transmission elastic recoil detection (TERD) and Rutherford backscattering spectroscopy (RBS) techniques not only with 5.4 MeV He2+ ion beam without absorber, but also 9 MeV O4+ ion beam with Al absorber. In experiments with 5.4 MeV He2+, well-resolved step-wise TERD spectra have been observed, from which thickness and Li composition of constituent films of the battery are directly estimated. The Li transport from LCO to Si films through LiPON as well as return-back of Li from Si to LCO films and Li leakage into the Al substrate out of the battery system by over-charging under charging condition have been observed in the experiments both 5.4 MeV He2+ and 9 MeV O4+. The latter result indicates that these techniques are applicable to testing degradation of the battery performance by repetition of charging and discharging. Both results are compared in details with each other.

QoS-aware integrated fiber-wireless standard compliant architecture based on XGPON and EDCA

NASA Astrophysics Data System (ADS)

Kaur, Ravneet; Srivastava, Anand

2018-01-01

Converged Fiber-Wireless (FiWi) broadband access network proves to be a promising candidate that is reliable, robust, cost efficient, ubiquitous and capable of providing huge amount of bandwidth. To meet the ever-increasing bandwidth requirements, it has become very crucial to investigate the performance issues that arise with the deployment of next-generation Passive Optical Network (PON) and its integration with various wireless technologies. Apart from providing high speed internet access for mass use, this combined architecture aims to enable delivery of high quality and effective e-services in different categories including health, education, finance, banking, agriculture and e-government. In this work, we present an integrated architecture of 10-Gigabit-capable PON (XG-PON) and Enhanced Distributed Channel Access (EDCA) that combines the benefits of both technologies to meet the QoS demands of subscribers. Performance evaluation of the standards-compliant hybrid network is done using discrete-event Network Simulator-3 (NS-3) and results are reported in terms of throughput, average delay, average packet loss rate and fairness index. Per-class throughput signifies effectiveness of QoS distribution whereas aggregate throughput indicates effective utilization of wireless channel. This work has not been reported so far to the best of our knowledge.

Plasma protein hydroperoxides during aging in humans: correlation with paraoxonase 1 (PON1) arylesterase activity and plasma total thiols.

PubMed

Mehdi, Mohammad Murtaza; Rizvi, Syed Ibrahim

2013-02-01

Oxidative stress is thought to play a major role in the development of several age-dependent diseases. Proteins are major targets for oxidative attack. Protein hydroperoxides are formed by hydroxyl and singlet oxygen attack on protein, forming relatively stable hydroperoxides on histidine, tyrosine and tryptophan residues. This study investigated the levels of plasma protein hydroperoxides and antioxidant potential of plasma during aging in humans. We correlated the protein hydroperoxide formation with plasma antioxidant potential, paraoxonase 1 (PON1) arylesterase activity and plasma total thiols. The protein hydroperoxides and antioxidant potential were measured in plasma of human subjects aged between 20 and 81 years of both genders. Increase in plasma protein hydroperoxides and decrease in plasma antioxidant potential were observed as function of human age. This study provides strong correlation between plasma protein hydroperoxides formation and decrease in plasma antioxidant potential during aging. PON1 arylesterase activity and plasma total thiols levels were also found to show significant correlation with increasing levels of plasma protein hydroperoxides during aging. The plasma protein hydroperoxides provide a reliable marker of long-term redox balance and degree of oxidative stress during aging process. Copyright © 2013 IMSS. Published by Elsevier Inc. All rights reserved.

Impact of diazotrophy on N stable isotope signatures of nitrate and particulate organic nitrogen: case studies in the north-eastern tropical Atlantic Ocean.

PubMed

Wannicke, Nicola; Liskow, Iris; Voss, Maren

2010-09-01

During two independent cruises in the north-eastern tropical Atlantic Ocean, we applied two different approaches to investigate the impact of diazotrophy on nitrogen stable isotope signatures in nitrate and particulate organic nitrogen (PON) of the food-web constituents. The first approach, used during the Poseidon cruise 348 in the Mauritanian upwelling, investigated the long-term influence of diazotrophy on the natural abundance of δ(15)N-NO(-)(3) and PON. The second approach, adopted during the Cape Verde field cruise, applied stable isotope tracer addition experiments. These served to determine the instantaneous transfer of diazotrophic N to the higher trophic level. Both approaches showed that N(2) fixation was compatible with the pattern and the magnitude of the isotopic depletion of dissolved NO(-)(3) during the Mauritanian upwelling cruise, as well as PON in zooplankton and phytoplankton during the Cape Verde cruises. An N-budget using (15)N incorporation rates and diazotrophic N(2) fixation rates showed that 6 % of the daily N(2) fixation was potentially taken up by the mesozooplankton community. Direct grazing accounted for 56 % of gross mesozooplanktonic N incorporation, while 46 % occurred due to channelling through the microbial loop.

Enhanced noise tolerance for 10 Gb/s Bi-directional cross-wavelength reuse colorless WDM-PON by using spectrally shaped OFDM signals

NASA Astrophysics Data System (ADS)

Choudhury, Pallab K.

2018-05-01

Spectrally shaped orthogonal frequency division multiplexing (OFDM) signal for symmetric 10 Gb/s cross-wavelength reuse reflective semiconductor optical amplifier (RSOA) based colorless wavelength division multiplexed passive optical network (WDM-PON) is proposed and further analyzed to support broadband services of next generation high speed optical access networks. The generated OFDM signal has subcarriers in separate frequency ranges for downstream and upstream, such that the re-modulation noise can be effectively minimized in upstream data receiver. Moreover, the cross wavelength reuse approach improves the tolerance against Rayleigh backscattering noise due to the propagation of different wavelengths in the same feeder fiber. The proposed WDM-PON is successfully demonstrated for 25 km fiber with 16-QAM (quadrature amplitude modulation) OFDM signal having bandwidth of 2.5 GHz for 10 Gb/s operation and subcarrier frequencies in 3-5.5 GHz and DC-2.5 GHz for downstream (DS) and upstream (US) transmission respectively. The result shows that the proposed scheme maintains a good bit error rate (BER) performance below the forward error correction (FEC) limit of 3.8 × 10-3 at acceptable receiver sensitivity and provides a high resilience against re-modulation and Rayleigh backscattering noises as well as chromatic dispersion.

Association of the atherogenic index of plasma and oxidative stress status with weight gain during non-complicated pregnancy.

PubMed

Stefanović, Aleksandra; Kotur-Stevuljević, Jelena; Vujović, Ana; Spasić, Slavica; Spasojević-Kalimanovska, Vesna; Jelic-Ivanović, Zorana; Martinović, Jelena; Ardalić, Daniela; Mandić-Marković, Vesna; Miković, Zeljko; Cerović, Nikola

2012-11-01

Pregnancy is a stressful condition linked with altered lipid profile, increased oxidative stress and increased inflammation processes. The purpose of the present study was to determine the associations between those alterations with increased weight gain during pregnancy. The atherogenic index of plasma (AIP) and oxidative stress status parameters were determinated in 50 healthy and 172 pregnant women with non-complicated pregnancy. Pregnant women were divided in four groups according to body mass index (BMI) values (BMI quartiles). Oxidative stress parameters were significantly lower in the control group compared with all the pregnant women quartiles. Unexpectedly, differences in oxidative stress parameters between BMI quartiles groups were not significant. The antioxidant defence parameters remained quite similar in the different BMI quartiles. Weight gain and paraoxonase-1 (PON1) activities were independently associated with increased AIP while weight gain and triglyceride concentration were found to be significant predictors of PON1 activities. The results of our current study indicate the association of maternal weight gain during pregnancy and altered lipid profile, elevated oxidative stress and changed antioxidative capacity of PON1. Taken together all these facts indicate possible increased risk of cardiovascular disease (CVD) development in later life if the weight gain during pregnancy is excessive.

The neuroprotective effect of lovastatin on MPP(+)-induced neurotoxicity is not mediated by PON2.

PubMed

Aguirre-Vidal, Yoshajandith; Montes, Sergio; Tristan-López, Luis; Anaya-Ramos, Laura; Teiber, John; Ríos, Camilo; Baron-Flores, Verónica; Monroy-Noyola, Antonio

2015-05-01

Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of the pigmented dopaminergic neurons in the substantia nigra pars compacta with subsequent striatal dopamine (DA) deficiency and increased lipid peroxidation. The etiology of the disease is still unclear and it is thought that PD may be caused by a combination of genetic and environmental factors. In the search of new pharmacological options, statins have been recognized for their potential application to treat PD, due to their antioxidant effect. The aim of this work is to contribute in the characterization of the neuroprotective effect of lovastatin in a model of PD induced by 1-methyl-4-phenylpyridinium (MPP(+)). Male Wistar rats (200-250 g) were randomly allocated into 4 groups and administered for 7 days with different pharmacological treatments. Lovastatin administration (5 mg/kg) diminished 40% of the apomorphine-induced circling behavior, prevented the striatal DA depletion and lipid peroxides formation by MPP(+) intrastriatal injection, as compared to the group of animals treated only with MPP(+). Lovastatin produced no change in paraoxonase-2 (PON2) activity. It is evident that lovastatin conferred neuroprotection against MPP(+)-induced protection but this effect was not associated with the induction of PON2 in the rat striatum. Copyright © 2015. Published by Elsevier B.V.

Paraoxonase 1 activity in subchronic low-level inorganic arsenic exposure through drinking water.

PubMed

Afolabi, Olusegun K; Wusu, Adedoja D; Ogunrinola, Olufunmilayo O; Abam, Esther O; Babayemi, David O; Dosumu, Oluwatosin A; Onunkwor, Okechukwu B; Balogun, Elizabeth A; Odukoya, Olusegun O; Ademuyiwa, Oladipo

2016-02-01

Epidemiological evidences indicate close association between inorganic arsenic exposure via drinking water and cardiovascular diseases. While the exact mechanism of this arsenic-mediated increase in cardiovascular risk factors remains enigmatic, epidemiological studies indicate a role for paraoxonase 1 (PON1) in cardiovascular diseases. To investigate the association between inorganic arsenic exposure and cardiovascular diseases, rats were exposed to sodium arsenite (trivalent; 50, 100, and 150 ppm As) and sodium arsenate (pentavalent; 100, 150, and 200 ppm As) in their drinking water for 12 weeks. PON1 activity towards paraoxon (PONase) and phenylacetate (AREase) in plasma, lipoproteins, hepatic, and brain microsomal fractions were determined. Inhibition of PONase and AREase in plasma and HDL characterized the effects of the two arsenicals. While the trivalent arsenite inhibited PONase by 33% (plasma) and 46% (HDL), respectively, the pentavalent arsenate inhibited the enzyme by 41 and 34%, respectively. AREase activity was inhibited by 52 and 48% by arsenite, whereas the inhibition amounted to 72 and 67%, respectively by arsenate. The pattern of inhibition in plasma and HDL indicates that arsenite induced a dose-dependent inhibition of PONase whereas arsenate induced a dose-dependent inhibition of AREase. In the VLDL + LDL, arsenate inhibited PONase and AREase while arsenite inhibited PONase. In the hepatic and brain microsomal fractions, only the PONase enzyme was inhibited by the two arsenicals. The inhibition was more pronounced in the hepatic microsomes where a 70% inhibition was observed at the highest dose of pentavalent arsenic. Microsomal cholesterol was increased by the two arsenicals resulting in increased cholesterol/phospholipid ratios. Our findings indicate that decreased PON1 activity observed in arsenic exposure may be an incipient biochemical event in the cardiovascular effects of arsenic. Modulation of PON1 activity by arsenic may also be mediated through changes in membrane fluidity brought about by changes in the concentration of cholesterol in the microsomes. © 2014 Wiley Periodicals, Inc.

Remote heterodyne millimeter-wave over fiber based OFDM-PON with master-to-slave injected dual-mode colorless FPLD pair.

PubMed

Chen, Hsiang-Yu; Chi, Yu-Chieh; Lin, Gong-Ru

2015-08-24

A remote heterodyne millimeter-wave (MMW) carrier at 47.7 GHz over fiber synthesized with the master-to-slave injected dual-mode colorless FPLD pair is proposed, which enables the future connection between the wired fiber-optic 64-QAM OFDM-PON at 24 Gb/s with the MMW 4-QAM OFDM wireless network at 2 Gb/s. Both the single- and dual-mode master-to-slave injection-locked colorless FPLD pairs are compared to optimize the proposed 64-QAM OFDM-PON. For the unamplified single-mode master, the slave colorless FPLD successfully performs the 64-QAM OFDM data at 24 Gb/s with EVM, SNR and BER of 8.5%, 21.5 dB and 2.9 × 10(-3), respectively. In contrast, the dual-mode master-to-slave injection-locked colorless FPLD pair with amplified and unfiltered master can transmit 64-QAM OFDM data at 18 Gb/s over 25-km SMF to provide EVM, SNR and BER of 8.2%, 21.8 dB and 2.2 × 10(-3), respectively. For the dual-mode master-to-slave injection-locked colorless FPLD pair, even though the modal dispersion occurred during 25-km SMF transmission makes it sacrifice the usable OFDM bandwidth by only 1 GHz, which guarantees the sufficient encoding bitrate for the optically generated MMW carrier to implement the fusion of MMW wireless LAN and DWDM-PON with cost-effective and compact architecture. As a result, the 47.7-GHz MMW carrier remotely beat from the dual-mode master-to-slave injection-locked colorless FPLD pair exhibits an extremely narrow bandwidth of only 0.48 MHz. After frequency down-conversion operation, the 47.7-GHz MMW carrier successfully delivers 4-QAM OFDM data up to 2 Gb/s with EVM, SNR and BER of 33.5%, 9.51 dB and 1.4 × 10(-3), respectively.

Simultaneous shifts in elemental stoichiometry and fatty acids of Emiliania huxleyi in response to environmental changes

NASA Astrophysics Data System (ADS)

Bi, Rong; Ismar, Stefanie M. H.; Sommer, Ulrich; Zhao, Meixun

2018-02-01

Climate-driven changes in environmental conditions have significant and complex effects on marine ecosystems. Variability in phytoplankton elements and biochemicals can be important for global ocean biogeochemistry and ecological functions, while there is currently limited understanding on how elements and biochemicals respond to the changing environments in key coccolithophore species such as Emiliania huxleyi. We investigated responses of elemental stoichiometry and fatty acids (FAs) in a strain of E. huxleyi under three temperatures (12, 18 and 24 °C), three N : P supply ratios (molar ratios 10:1, 24:1 and 63:1) and two pCO2 levels (560 and 2400 µatm). Overall, C : N : P stoichiometry showed the most pronounced response to N : P supply ratios, with high ratios of particulate organic carbon vs. particulate organic nitrogen (POC : PON) and low ratios of PON vs. particulate organic phosphorus (PON : POP) in low-N media, and high POC : POP and PON : POP in low-P media. The ratio of particulate inorganic carbon vs. POC (PIC : POC) and polyunsaturated fatty acid proportions strongly responded to temperature and pCO2, both being lower under high pCO2 and higher with warming. We observed synergistic interactions between warming and nutrient deficiency (and high pCO2) on elemental cellular contents and docosahexaenoic acid (DHA) proportion in most cases, indicating the enhanced effect of warming under nutrient deficiency (and high pCO2). Our results suggest differential sensitivity of elements and FAs to the changes in temperature, nutrient availability and pCO2 in E. huxleyi, which is to some extent unique compared to non-calcifying algal classes. Thus, simultaneous changes of elements and FAs should be considered when predicting future roles of E. huxleyi in the biotic-mediated connection between biogeochemical cycles, ecological functions and climate change.

Origin and biochemical cycling of particulate nitrogen in the Mandovi estuary

NASA Astrophysics Data System (ADS)

Fernandes, Loreta

2011-09-01

Mandovi estuary is a tropical estuary strongly influenced by the southwest monsoon. In order to understand, sources and fate of particulate organic nitrogen, suspended particulate matter (SPM) collected from various locations, was analyzed for particulate organic carbon (POC) and particulate organic nitrogen (PON), δ 13C POC, total hydrolysable amino acid enantiomers ( L- and D- amino acids) concentration and composition. δ 13C POC values were depleted (-32 to -25‰) during the monsoon and enriched (-29.6 to -21‰) in the pre-monsoon season implying that OM was derived from terrestrial and marine sources during the former and latter season, respectively. The biological indicators such as C/N ratio, D-amino acids, THAA yields and degradation indices (DI) indicate that the particulate organic matter (POM) was relatively more degraded during the monsoon season. Conversely, during the pre-monsoon, the biological indicators indicated the presence of relatively fresh and labile POM derived from autochthonous sources. Amino acids such as alanine, aspartic acid, leucine, serine, arginine, and threonine in monsoon and glutamic acid, glycine, valine, lysine, and isoleucine in pre-monsoon were relatively abundant. Presence of bacterial biomarker, D-amino acids in the SPM of the estuary during both the seasons signifies important contribution of bacteria to the estuarine detrital ON pool. Based on D-amino acid yields, bacterial OM accounted for 16-34% (23.0 ± 6.7%) of POC and 29-75% (47.9 ± 18.7%) of PON in monsoon, and 30-78% (50.0 ± 15%) of POC and 34-79% (51.2 ± 13.3%) of the PON in pre-monsoon in the estuary. Substantial contribution of bacterial-N to PON indicates nitrogen (N) enrichment on terrestrial POM during the monsoon season. Transport of terrestrial POM enriched with bacterial OM to the coastal waters is expected to influence coastal productivity and ecosystem functioning during the monsoon season.

Visual event-related potential changes in two subtypes of multiple system atrophy, MSA-C and MSA-P.

PubMed

Kamitani, Toshiaki; Kuroiwa, Yoshiyuki; Wang, Lihong; Li, Mei; Suzuki, Yume; Takahashi, Tatsuya; Ikegami, Tadashi; Matsubara, Sho

2002-08-01

We investigated the visual event-related potentials (ERPs) in two subtypes of multisystem atrophy (MSA) in 15 MSA-C patients, 12 MSA-P patients, and 21 normal control (NC) subjects. We used a visual oddball task to elicit ERPs. No significant changes were seen in N1 or N2 latency, in either MSA-C or MSA-P, compared with the NC group. An early stage of visual information process related to N1 and a visual discrimination process related to N2 might be preserved in both MSA-C and MSA-P. The P3a peak was more frequently undetectable in MSA than in the NC group. Significant P3a amplitude reduction in both MSA-C and MSA-P suggests impairment of the automatic cognitive processing in both MSA-C and MSA-P. Significant difference was found in P3b latency and P3b amplitude only in MSA-C, compared with the NC group. The result suggests the impairment of the controlled cognitive processing after the visual discrimination process in the MSA-C group. We further investigated the correlation between visual ERP changes and magnetic resonance imaging (MRI) data. Quantitative MRI measurements showed reduced size of the pons, cerebellum, perisylvian cerebral area, and deep cerebral gray matter in both MSA-C and MSA-P, and of the corpus callosum only in MSA-P, as compared to NC group. In both MSA-C and MSA-P, P3b latency was significantly correlated with the size on MRI of the pons and the cerebellum. P3b latency in the whole MSA group was also significantly correlated with the size of the pons and the cerebellum. These results indicate that P3b latency changes in parallel with the volume of the pons and the cerebellum in both MSA-C and MSA-P.

Handheld Raman Spectrometer Instrumentation for Quantitative Tuberculosis Biomarker Detection: A Performance Assessment for Point-of-Need Infectious Disease Diagnostics.

PubMed

Owens, Nicholas A; Laurentius, Lars B; Porter, Marc D; Li, Qun; Wang, Sean; Chatterjee, Delphi

2018-01-01

Techniques for the detection of disease biomarkers are key components in the protection of human health. While work over the last few decades has redefined the low-level measurement of disease biomarkers, the translation of these capabilities from the formal clinical setting to point-of-need (PON) usage has been much more limited. This paper presents the results of experiments designed to examine the potential utility of a handheld Raman spectrometer as a PON electronic reader for a sandwich immunoassay based on surface-enhanced Raman scattering (SERS). In so doing, the study herein used a recently developed procedure for the SERS detection of phospho-myo-inositol-capped lipoarabinomannan (PILAM) as a means to compare the performance of laboratory-grade and handheld instrumentation and, therefore, gauge the utility of the handheld instrument for PON deployment. Phospho-myo-inositol-capped lipoarabinomannan is a non-pathogenic simulant for mannose-capped lipoarabinomannan (ManLAM), which is an antigenic marker found in serum and other body fluids of individuals infected with tuberculosis (TB). The results of the measurements with the field-portable spectrometer were then compared to those obtained for the same samples when using a much more sensitive benchtop Raman spectrometer. The results, albeit under different operational settings for the two spectrometers (e.g., signal integration time), are promising in that the limit of detection found for PILAM spiked in human serum when using the handheld system (0.18 ng/mL) approached that of the benchtop instrument (0.032 ng/mL). This work also: (1) identified potential adaptations (e.g., optimization of the plasmonically enhanced response for measurement by the handheld unit through a change in the excitation wavelength) to tighten the gap in performance; and (2) briefly examined the next steps and potential processes required to move this immunoassay platform closer to PON utility.

CT-angiography source images indicate less fatal outcome despite coma of patients in the Basilar Artery International Cooperation Study.

PubMed

Pallesen, Lars P; Khomenko, Andrei; Dzialowski, Imanuel; Barlinn, Jessica; Barlinn, Kristian; Zerna, Charlotte; van der Hoeven, Erik Jrj; Algra, Ale; Kapelle, L Jaap; Michel, Patrik; Bodechtel, Ulf; Demchuk, Andrew M; Schonewille, Wouter; Puetz, Volker

2017-02-01

Background Coma is associated with poor outcome in patients with basilar artery occlusion. Aims We sought to assess whether the posterior circulation Acute Stroke Prognosis Early CT Score and the Pons-Midbrain Index applied to CT angiography source images predict the outcome of comatose patients in the Basilar Artery International Cooperation Study. Methods Basilar Artery International Cooperation Study was a prospective, observational registry of patients with acute basilar artery occlusion with 48 recruiting centers worldwide. We applied posterior circulation Acute Stroke Prognosis Early CT Score and Pons-Midbrain Index to CT angiography source images of Basilar Artery International Cooperation Study patients who presented with coma. We calculated adjusted risk ratios to assess the association of dichotomized posterior circulation Acute Stroke Prognosis Early CT Score (≥8 vs. <8) and Pons-Midbrain Index (<3 vs. ≥3) with mortality and favourable outcome (modified Rankin Scale score 0-3) at one month. Results Of 619 patients in the Basilar Artery International Cooperation Study registry, CT angiography source images were available for review in 158 patients. Among these, 78 patients (49%) presented with coma. Compared to non-comatose patients, comatose patients were more likely to die (risk ratios 2.34; CI 95% 1.56-3.52) and less likely to have a favourable outcome (risk ratios 0.44; CI 95% 0.24-0.80). Among comatose patients, a Pons-Midbrain Index < 3 was related to reduced mortality (adjusted RR 0.66; 95% CI 0.46-0.96), but not to favourable outcome (adjusted RR 1.19; 95% CI 0.39-3.62). Posterior circulation Acute Stroke Prognosis Early CT Score dichotomized at ≥ 8 vs. <8 was not significantly associated with death (adjusted RR 0.70; 95% CI 0.46-1.05). Conclusion In comatose patients with basilar artery occlusion, the extent of brainstem ischemia appears to be related to mortality but not to favourable outcome.

Variability in runoff fluxes of dissolved and particulate carbon and nitrogen from two watersheds of different tree species during intense storm events

NASA Astrophysics Data System (ADS)

Lee, Mi-Hee; Payeur-Poirier, Jean-Lionel; Park, Ji-Hyung; Matzner, Egbert

2016-09-01

Heavy storm events may increase the amount of organic matter in runoff from forested watersheds as well as the relation of dissolved to particulate organic matter. This study evaluated the effects of monsoon storm events on the runoff fluxes and on the composition of dissolved (< 0.45 µm) and particulate (0.7 µm to 1 mm) organic carbon and nitrogen (DOC, DON, POC, PON) in a mixed coniferous/deciduous (mixed watershed) and a deciduous forested watershed (deciduous watershed) in South Korea. During storm events, DOC concentrations in runoff increased with discharge, while DON concentrations remained almost constant. DOC, DON and NO3-N fluxes in runoff increased linearly with discharge pointing to changing flow paths from deeper to upper soil layers at high discharge, whereas nonlinear responses of POC and PON fluxes were observed likely due to the origin of particulate matter from the erosion of mineral soil along the stream benches. The integrated C and N fluxes in runoff over the 2-month study period were in the order of DOC > POC and NO3-N > DON > PON. The integrated DOC fluxes in runoff during the study period were much larger at the deciduous watershed (16 kg C ha-1) than at the mixed watershed (7 kg C ha-1), while the integrated NO3-N fluxes were higher at the mixed watershed (5.2 kg N ha-1) than at the deciduous watershed (2.9 kg N ha-1). The latter suggests a larger N uptake by deciduous trees. Integrated fluxes of POC and PON were similar at both watersheds. The composition of organic matter in soils and runoff indicates that the contribution of near-surface flow to runoff was larger at the deciduous than at the mixed watershed. Our results demonstrate different responses of particulate and dissolved C and N in runoff to storm events as a combined effect of tree species composition and watershed specific flow paths.

Development of the precerebellar nuclei in the rat: IV. The anterior precerebellar extramural migratory stream and the nucleus reticularis tegmenti pontis and the basal pontine gray.

PubMed

Altman, J; Bayer, S A

1987-03-22

Sequential thymidine radiograms from rats injected on days E16, E17, E18, and E19 and killed 2 hours after injection and at daily intervals up to day E22 were used to establish the site of origin, migratory route, and settling patterns of neurons of the nucleus reticularis tegmenti pontis and basal pontine gray. The nucleus reticularis tegmenti pontis neurons, which are produced predominantly on days E15 and E16, derive from the primary precerebellar neuroepithelium. These cells, unlike those of the lateral reticular and external cuneate nuclei, take an anteroventral subpial route, forming the anterior precerebellar extramural migratory stream. This migratory stream reaches the anterior pole of the pons by day E18. In rats injected on day E16 and killed on day E18 some of the cells that reach the pons are unlabeled, indicating that they represent the early component of neurons generated on day E15. The cells labeled on day E16 begin to settle in the pons on day E19, 3 days after their production. These cells, migrating in an orderly temporal sequence, form a posterodorsal-to-anteroventral gradient in the nucleus reticularis tegmenti pontis. Unlike the neurons of all the other precerebellar nuclei, the basal pontine gray neurons derive from the secondary precerebellar neuroepithelium. The secondary precerebellar neuroepithelium forms on day E16 as an outgrowth of the primary precerebellar neuroepithelium, and it remains mitotically active through day E19, spanning the entire period of basal pontine gray neurogenesis. The secondary precerebellar neuroepithelium is surrounded by a horizontal layer of postmitotic cells, representing the head-waters of the anterior precerebellar extramural migratory stream. In rats injected on day E18 and killed on day E19 the cells are labeled in the proximal half of the stream around the medulla but those closer to the pons are unlabeled, indicating an orderly sequence of migration. In rats injected on day E18 and killed on day E20 the labeled cells reach the pole of the pons. In the basal pontine gray the sequentially generated neurons settle in a precise order. The neurons generated on day E16 form a small core posteriorly and the neurons generated on days E17, E18, and E19 form regular concentric rings around the core in an inside-out sequence.

Four-fold increase in users of time-wavelength division multiplexing (TWDM) passive optical network (PON) by delayed optical amplitude modulation (AM) upstream

NASA Astrophysics Data System (ADS)

Kachhatiya, Vivek; Prince, Shanthi

2016-12-01

In this paper, we have proposed and simulated optical time division multiplexed passive optical network (TDM-PON) using delayed optical amplitude modulation (AM). Eight upstream wavelengths are demonstrated to show optical time wavelength division multiplexed (TWDM) by combining optical network units (ONU) users data at the remote node (RN). Each ONU generates 2.5 Gb/s user data, and it is modulated using novel return to zero (RZ) delayed AM. Optical TDM aggregates 10 Gb/s data per wavelength from four 2.5 Gb/s upstream user data, which facilitates four different ONU data on the same wavelength as 10 Gb/s per upstream wavelength and, simplify the laser requirements (2.5 Gb/s) at each optical network unit (ONU) transmitter. Upstream optical TWDM-PON is investigated for eight wavelengths with wavelength spacing of 100 GHz. Novel optical TDM for upstream increased the number of the simultaneous user to fourfold from conventional TWDM-PON using delayed AM with a high-quality-factor of received signal. Despite performance degradation due to different fiber reach and dispersion compensation technique, Optical TWDM link shows significant improvement regarding receiver sensitivity when compared with common TWDM link. Hence, it offers optimistic thinking to show optical TDM at this phase as one of the future direction, where complex digital signal processing (DSP) and coherent optical communication are frequently demonstrated to serve the access network. Downstream side conventional TWDM eight wavelengths are multiplexed at the OLT and sent downstream to serve distributed tunable ONU receivers through an optical distribution network (ODN). Each downstream wavelengths are modulated at the peak rate of 10 Gb/s using non-return to zero external modulation (NRZ-EM). The proposed architecture is cost efficient and supports high data rates as well as ;pay as you grow; network for both service providers and the users perspectives. Users are classified into two categories viz home-user and business-user, with an option for easy up-gradation. Proposed architecture operates on next generation passive optical network stage 2 (NG-PON2) wavelength plan, with symmetrical data rate. Downstream performance is investigated by comparing, high power laser source with a conventional laser source and the L-band Erbium-doped fiber amplifier (EDFA) of gain 10 dB and 20 dB. Downstream eight wavelengths perform error-free up to 40 Km fiber reach and 1024 splitting points. Power budget of the proposed architecture incorporates the N1, N2, E1 and E2 optical path loss class.

Fiber-Bragg-Grating-Based Optical Code-Division Multiple Access Passive Optical Network Using Dual-Baseband Modulation Scheme

NASA Astrophysics Data System (ADS)

Lin, Wen-Piao; Wu, He-Long

2005-08-01

We propose a fiber-Bragg-grating (FBG)-based optical code-division multiple access passive optical network (OCDMA-PON) using a dual-baseband modulation scheme. A mathematical model is developed to study the performance of this scheme. According to the analyzed results, this scheme can allow a tolerance of the spectral power distortion (SPD) ratio of 25% with a bit error rate (BER) of 10-9 when the modified pseudorandom noise (PN) code length is 16. Moreover, we set up a simulated system to evaluate the baseband and radio frequency (RF) band transmission characteristics. The simulation results demonstrate that our proposed OCDMA-PON can provide a cost-effective and scalable fiber-to-the-home solution.

AWG-based WDM-PON monitoring system using an optical switch and a WDM filter

NASA Astrophysics Data System (ADS)

Liaw, S.-K.; Lai, Y.-T.; Chang, C.-L.; Shung, O.

2008-09-01

A new WDM-PON scheme with real-time monitoring based on a time-sharing method is proposed. It uses an optical time domain reflectometer (OTDR) to monitor multiple ports by integrating an optical switch (OSW) with a dense wavelength division multiplexer (DWDM) at the optical line terminal (OLT) site. Each downstream signal and its corresponding monitoring signal are separated by m times the free-space range (FSR) of an array waveguide grating (AWG). A bit error rate (BER) test in 2.5 Gb/s × 27 km is performed with and without turning on the OTDR. A small power penalty of 0.7 dB is observed compared to the back-to-back measurement.

Sleep neurobiology from a clinical perspective.

PubMed

España, Rodrigo A; Scammell, Thomas E

2011-07-01

Many neurochemical systems interact to generate wakefulness and sleep. Wakefulness is promoted by neurons in the pons, midbrain, and posterior hypothalamus that produce acetylcholine, norepinephrine, dopamine, serotonin, histamine, and orexin/hypocretin. Most of these ascending arousal systems diffusely activate the cortex and other forebrain targets. NREM sleep is mainly driven by neurons in the preoptic area that inhibit the ascending arousal systems, while REM sleep is regulated primarily by neurons in the pons, with additional influence arising in the hypothalamus. Mutual inhibition between these wake- and sleep-regulating regions likely helps generate full wakefulness and sleep with rapid transitions between states. This up-to-date review of these systems should allow clinicians and researchers to better understand the effects of drugs, lesions, and neurologic disease on sleep and wakefulness.

Demonstration of hybrid orbital angular momentum multiplexing and time-division multiplexing passive optical network.

PubMed

Wang, Andong; Zhu, Long; Liu, Jun; Du, Cheng; Mo, Qi; Wang, Jian

2015-11-16

Mode-division multiplexing passive optical network (MDM-PON) is a promising scheme for next-generation access networks to further increase fiber transmission capacity. In this paper, we demonstrate the proof-of-concept experiment of hybrid mode-division multiplexing (MDM) and time-division multiplexing (TDM) PON architecture by exploiting orbital angular momentum (OAM) modes. Bidirectional transmissions with 2.5-Gbaud 4-level pulse amplitude modulation (PAM-4) downstream and 2-Gbaud on-off keying (OOK) upstream are demonstrated in the experiment. The observed optical signal-to-noise ratio (OSNR) penalties for downstream and upstream transmissions at a bit-error rate (BER) of 2 × 10(-3) are less than 2.0 dB and 3.0 dB, respectively.

On-the-field performance of quintuple-play long-reach OFDM-based WDM-PON optical access networks.

PubMed

Llorente, Roberto; Morant, Maria; Pellicer, Eloy; Herman, Milan; Nagy, Zsolt; Alves, Tiago; Cartaxo, Adolfo; Herrera, Javier; Correcher, Jose; Quinlan, Terence; Walker, Stuart; Rodrigues, Cláudio; Cluzeaud, Pierre; Schmidt, Axel; Piesiewicz, Radoslaw; Sambaraju, Rakesh

2014-03-24

In this paper the on-the-field performance of a WDM-PON optical access providing quintuple-play services using orthogonal frequency division multiplexing (OFDM) modulation is evaluated in a real fiber-to-the-home (FTTH) network deployed by Towercom operator in Bratislava (Slovakia). A bundle of quintuple-play services comprising full-standard OFDM-based signals (LTE, WiMAX, UWB and DVB-T) and an ad-hoc OFDM-GbE signal is transmitted in coexistence per single user. Both downstream and upstream transmission performances are evaluated in different on-the-field long-reach optical link distance configurations. Four wavelength multi-user transmission of quintuple-play OFDM services is demonstrated exceeding 60.8 km reach in standard single mode fiber.

2x2 MIMO-OFDM Gigabit fiber-wireless access system based on polarization division multiplexed WDM-PON.

PubMed

Deng, Lei; Pang, Xiaodan; Zhao, Ying; Othman, M B; Jensen, Jesper Bevensee; Zibar, Darko; Yu, Xianbin; Liu, Deming; Monroy, Idelfonso Tafur

2012-02-13

We propose a spectral efficient radio over wavelength division multiplexed passive optical network (WDM-PON) system by combining optical polarization division multiplexing (PDM) and wireless multiple input multiple output (MIMO) spatial multiplexing techniques. In our experiment, a training-based zero forcing (ZF) channel estimation algorithm is designed to compensate the polarization rotation and wireless multipath fading. A 797 Mb/s net data rate QPSK-OFDM signal with error free (<1 × 10(5)) performance and a 1.59 Gb/s net data rate 16QAM-OFDM signal with BER performance of 1.2 × 10(2) are achieved after transmission of 22.8 km single mode fiber followed by 3 m and 1 m air distances, respectively.

MIMO-OFDM WDM PON with DM-VCSEL for femtocells application.

PubMed

Othman, M B; Deng, Lei; Pang, Xiaodan; Caminos, J; Kozuch, W; Prince, K; Yu, Xianbin; Jensen, Jesper Bevensee; Monroy, I Tafur

2011-12-12

We report on experimental demonstration of 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20 km WDM-PON with directly modulated (DM) VCSELs for femtocells application. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Error-free signal demodulation of 64 subcarrier 4-QAM signals modulated at 198.5 Mb/s net data rate is achieved after fiber and 2 m indoor wireless transmission. We report BER of 7x10(-3) at the receiver for 16-QAM signals modulated at 397 Mb/s after 1 m of wireless transmission. Performance dependence on different wireless transmission path lengths, antenna separation, and number of subcarriers have been investigated. © 2011 Optical Society of America

A comparative quantitative analysis of magnetic susceptibility artifacts in echo planar and PROPELLER diffusion-weighted images

NASA Astrophysics Data System (ADS)

Cho, Jae-Hwan; Lee, Hae-Kag; Yang, Han-Joon; Lee, Gui-Won; Park, Yong-Soon; Chung, Woon-Kwan

2013-01-01

In this study, the authors investigated whether periodically-rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging (DWI) can remove magnetic susceptibility artifacts and compared apparent diffusion coefficient (ADC) values for PROPELLER DWI and the common echo planar (EP) DWI. Twenty patients that underwent brain MRI with a metal dental implant were selected. A 3.0T MR scanner was then used to obtain EP DWI, PROPELLER DWI, and corresponding apparent diffusion coefficient (ADC) maps for a b-value of 0 and 1,000 s/mm2. The frequencies of magnetic susceptibility artifacts in four parts of the brain (bilateral temporal lobes, pons, and orbit) were selected. In the ADC maps, we measured the ADC values of both sides of the temporal lobe and the pons. According to the study results, the frequency of magnetic susceptibility artifacts in PROPELLER DW images was lower than it was in EP DW images. In ADC maps, the ADC values of the bilateral temporal lobes and the pons were all higher in PROPELLER ADC maps than in EP ADC maps. Our findings show that when a high-field MRI machine is used, magnetic susceptibility artifacts can distort anatomical structures and produce high-intensity signals. Furthermore, our findings suggest that in many cases, PROPELLER DWI would be helpful in terms of achieving a correct diagnosis.

Pulsed laser-based optical frequency comb generator for high capacity wavelength division multiplexed passive optical network supporting 1.2 Tbps

NASA Astrophysics Data System (ADS)

Ullah, Rahat; Liu, Bo; Zhang, Qi; Saad Khan, Muhammad; Ahmad, Ibrar; Ali, Amjad; Khan, Razaullah; Tian, Qinghua; Yan, Cheng; Xin, Xiangjun

2016-09-01

An architecture for flattened and broad spectrum multicarriers is presented by generating 60 comb lines from pulsed laser driven by user-defined bit stream in cascade with three modulators. The proposed scheme is a cost-effective architecture for optical line terminal (OLT) in wavelength division multiplexed passive optical network (WDM-PON) system. The optical frequency comb generator consists of a pulsed laser in cascade with a phase modulator and two Mach-Zehnder modulators driven by an RF source incorporating no phase shifter, filter, or electrical amplifier. Optical frequency comb generation is deployed in the simulation environment at OLT in WDM-PON system supports 1.2-Tbps data rate. With 10-GHz frequency spacing, each frequency tone carries data signal of 20 Gbps-based differential quadrature phase shift keying (DQPSK) in downlink transmission. We adopt DQPSK-based modulation technique in the downlink transmission because it supports 2 bits per symbol, which increases the data rate in WDM-PON system. Furthermore, DQPSK format is tolerant to different types of dispersions and has a high spectral efficiency with less complex configurations. Part of the downlink power is utilized in the uplink transmission; the uplink transmission is based on intensity modulated on-off keying. Minimum power penalties have been observed with excellent eye diagrams and other transmission performances at specified bit error rates.

Further study on the effects of achatin-I, an Achatina endogenous neuroexcitatory tetrapeptide having a D-phenylalanine residue, on Achatina neurones.

PubMed

Takeuchi, H; Emaduddin, M; Araki, Y; Zhang, W; Han, X Y; Salunga, T L; Wong, S M

1995-01-01

Achatin-I (Gly-D-Phe-Ala-Asp), a tetrapeptide having a D-phenylalanine residue and isolated from Achatina ganglia, has been proposed as an excitatory neurotransmitter of Achatina neurones. In the present study, it was demonstrated using Achatina giant neurones that achetin-I, perfused at alow concentration, enhanced an inward current (Iin) caused by 5-hydroxytryptamine (fast component) and an outward current (Iout) caused by FMRFamide (Phe-Met-Arg-Phe-NH2), and that this peptide suppressed an Iin caused by oxytocin, and Iout caused by acetylcholine and APGW-amide (Ala-Pro-Gly-Trp-NH2). These findings indicate that achatin-I acts not only as a neurotransmitter but also as a neuromodulator for these neurones. In the preliminary experiments, it was shown that an Iin caused by achatin-I on an Achatina giant neurone type, PON (periodically oscillating neurone), was suppressed by H-89 (a PKA inhibitor) and W-7 (calmodulin inhibitor), and that an Iin caused by achatin-I on v-RCON (ventral-right cerebral distinct neurone) was suppressed by KT5823 (PKG inhibitor), suggesting that achatin-I acts on PON via the cyclic AMP-PKA system and on v-RCON via the cyclic GMP-PKG system. Moreover, calmodulin would play a role to produce the Iin for achatin-I on PON via the system mentioned.

Evaluation of oxidative stress status and antioxidant capacity in patients with renal cell carcinoma.

PubMed

Aldemir, Mustafa; Karaguzel, Ersagun; Okulu, Emrah; Gudeloglu, Ahmet; Ener, Kemal; Ozayar, Asim; Erel, Ozcan

2015-01-01

We evaluated and compared the serum oxidative stress and antioxidant enzymes in patients with renal cell carcinoma (RCC) and the control group. The prospective study consisted of 97 patients with RCC (Group 1) and 80 age and sex matched healthy volunteers (Group 2). Group 1 and 2 were compared concerning serum mean total oxidant status (TOS), total antioxidant capacity (TAC), paraoxonase-1 (PON-1), arylesterase, total thiol, catalase (CAT), myeloperoxidase (MPO) and ceruloplasmin. Patients' mean age was 58.5 ±12.3 and 56.9 ±15.8 years, respectively, in Group 1 and 2. No statistically significant differences were detected between the groups in terms of oxidative stress parameters and antioxidant capacity measured in the serum of patients including, TOS, TAC, PON1, arylesterase, total thiol, CAT, MPO, and ceruloplasmin levels (p >0.05 for all parameters). The PON-1 value was significantly higher in patients with pT1 stage than pT3 stage (p = 0.007). The arylesterase value was significantly higher in patients with Fuhrman's nuclear grade 3 than grade 2 (p = 0.035). There was no correlation between these parameters level and Fuhrman's nuclear grade, stage, or histopathological tumor type. Our results demonstrated that evaluation of these parameters in the serum of patients with localized RCC may not be used as a marker to discriminate between patients with RCC and healthy people.

Differential effects of age and sex on the cerebellar hemispheres and the vermis: a prospective MR study.

PubMed

Raz, N; Dupuis, J H; Briggs, S D; McGavran, C; Acker, J D

1998-01-01

The purpose of this study was to determine the effects of age and sex on the size of the cerebellar hemispheres, the cerebellar vermis, and the pons in healthy adults. We estimated the volumes of the cerebellar hemispheres (excluding the vermis and the peduncles), the cross-sectional area of the vermis, and the cross-sectional area of the ventral pons from MR images obtained in 146 healthy volunteers, 18 to 77 years old. We found a mild but significant age-related reduction in the volume of the cerebellar hemispheres and in the total area of the cerebellar vermis; however, the analysis of age trends in the vermian lobules revealed differential age-related declines. The areas of lobules VI and VII and of the posterior vermian lobules (VIII-X) declined significantly with age, whereas the anterior vermis (I-V) showed no significant age-related shrinkage. The volume of the cerebellar hemispheres (especially the right) and the area of the anterior vermis were greater in men, even after adjustment for height. Neither age nor sex affected the area of the ventral pons. Normal aging of the cerebellum is associated with selective regional shrinkage. The cerebellar hemispheres and the area of the anterior vermis may be larger in men than in women regardless of differences in body size.

Individuals with autism have higher 8-Iso-PGF2α levels than controls, but no correlation with quantitative assay of Paraoxonase 1 serum levels.

PubMed

Pop, Bianca; Niculae, Alexandru-Ștefan; Pop, Tudor Lucian; Răchișan, Andreea Liana

2017-12-01

Autism spectrum disorder (ASD) represents a very large set of neurodevelopmental issues with diverse clinical outcomes. Various hypotheses have been put forth for the etiology of autism spectrum disorder, including issues pertaining to oxidative stress. In this study, we conducted measurements of serum 8-Iso-Prostaglanding F2 α (8-iso-PGF2α, which is the results of non-enzimatically mediated polyunsaturated fatty acid oxidation) in a population of individuals with autism and a control group of age and sex matched controls. A quantitative assay of Paraoxonase 1 (PON1) was conducted. Data regarding comorbidities, structural MRI scans, medication, intelligence quotient (IQ) and Childhood Autism Rating Scale scores (CARS) were also included in our study. Our results show that patients diagnosed with autism have higher levels of 8-iso-PGF2α than their neurotypical counterparts. Levels of this particular metabolite, however, do not correlate with quantitative serum levels of Paraoxonase 1, which has been shown to be altered in individuals with autism. Neither 8-iso-PGF2α nor quantitative levels of PON1 provide any meaningful correlation with clinical or neuroimaging data in this study group. Future research should focus on providing data regarding PON 1 phenotype, in addition to standard quantitative measurements, in relation to 8-iso-PGF2α as well as other clinical and structural brain findings.

Software Defined Networking for Next Generation Converged Metro-Access Networks

NASA Astrophysics Data System (ADS)

Ruffini, M.; Slyne, F.; Bluemm, C.; Kitsuwan, N.; McGettrick, S.

2015-12-01

While the concept of Software Defined Networking (SDN) has seen a rapid deployment within the data center community, its adoption in telecommunications network has progressed slowly, although the concept has been swiftly adopted by all major telecoms vendors. This paper presents a control plane architecture for SDN-driven converged metro-access networks, developed through the DISCUS European FP7 project. The SDN-based controller architecture was developed in a testbed implementation targeting two main scenarios: fast feeder fiber protection over dual-homed Passive Optical Networks (PONs) and dynamic service provisioning over a multi-wavelength PON. Implementation details and results of the experiment carried out over the second scenario are reported in the paper, showing the potential of SDN in providing assured on-demand services to end-users.

Monolithically integrated distributed feedback laser array wavelength-selectable light sources for WDM-PON application

NASA Astrophysics Data System (ADS)

Chen, Xin; Zhao, Jianyi; Zhou, Ning; Huang, Xiaodong; Cao, Mingde; Wang, Lei; Liu, Wen

2015-01-01

The monolithic integration of 1.5-μm four channels phase shift distributed feedback lasers array (DFB-LD array) with 4×1 multi-mode interference (MMI) optical combiner is demonstrated. A home developed process mainly consists of butt-joint regrowth (BJR) and simultaneous thermal and ultraviolet nanoimprint lithography (STU-NIL) is implemented to fabricate gratings and integrated devices. The threshold currents of the lasers are less than 10 mA and the side mode suppression ratios (SMSR) are better than 40 dB for all channels. Quasi-continuous tuning is realized over 7.5 nm wavelength region with the 30 °C temperature variation. The results indicate that the integration device we proposed can be used in wavelength division multiplexing passive optical networks (WDM-PON).

16-channel arrayed waveguide grating (AWG) demultiplexer design on SOI wafer for application in CWDM-PON

NASA Astrophysics Data System (ADS)

Juhari, Nurjuliana; Menon, P. Susthitha; Ehsan, Abang Annuar; Shaari, Sahbudin

2015-01-01

Arrayed Waveguide Grating (AWG) functioning as a demultiplexer is designed on SOI platform with rib waveguide structure to be utilized in coarse wavelength division multiplexing-passive optical network (CWDM-PON) systems. Two design approaches; conventional and tapered configuration of AWG was developed with channel spacing of 20 nm that covers the standard transmission spectrum of CWDM ranging from 1311 nm to 1611 nm. The performance of insertion loss for tapered configuration offered the lowest insertion loss of 0.77 dB but the adjacent crosstalk gave non-significant relation for both designs. With average channel spacing of 20.4 nm, the nominal central wavelength of this design is close to the standard CWDM wavelength grid over 484 nm free spectrum range (FSR).

Cost-effective WDM-PON Delivering Up/Down-stream Data on a Single Wavelength Using Soliton Pulse

NASA Astrophysics Data System (ADS)

Tawade, Laxman

2013-06-01

This paper presents wavelength division multiplexing passive optical network (WDM-PON) system delivering downstream 2.5 Gbit/s data and upstream 1 Gbit/s data on a single wavelength using pulse source is mode locked laser which generating a single pulse of "sech" shape with specified power and width i.e. soliton pulse. The optical source for downstream data and upstream data is sech pulse generator at central office and reflective semiconductor optical amplifier (RSOA) at each optical network unit. We also investigate analysis of backscattered optical signal for upstream data and downstream data simultaneously. Bit error rate, Q-Factor were measured to demonstrate the proposed scheme. In this paper Long reach aspects of an access network is investigated using single channel scenario.

Compound oxidized styrylphosphine. [flame resistant vinyl polymers

NASA Technical Reports Server (NTRS)

Paciorek, K. J. L. (Inventor)

1979-01-01

A process is described for preparing flame resistant, nontoxic vinyl polymers which contain phosphazene groups and which do not emit any toxic or corrosive products when they are oxidatively degraded. Homopolymers, copolymers, and terpolymers of a styrene based monomer are prepared by polymerizing at least one oxidized styrylphosphine monomer from a group of organic azides, or by polymerizing p-diphenylphosphinestyrene and then oxidizing that monomer with an organoazide from the group of (C6H5)2P(O)N3, (C6H5O)2P(O)N3, (C6H5)2C3N3(N3), and C6H5C3N3(N3)2. Copolymers can also be prepared by copolymerizing styrene with at least one oxidized styrylphosphine monomer.

Analysis of the influence of backscattered optical power over bidirectional PON links

NASA Astrophysics Data System (ADS)

Martínez, J. J.; Garcés, I.; López, A.; Villafranca, A.; Losada, M. A.

2010-05-01

Our aim is to describe the behavior of non-linear scattering effects that arise in standard single mode fiber (SMF), specifically scattering effects that propagate optical power in the reverse direction of the source signal such as Rayleigh Scattering (RS) and Brillouin Scattering (BS). For this purpose, the effects of backscattering phenomena over a bidirectional data transmission in a passive optical network (PON) scheme have been assessed. The impact of these high optical power components over reception at the optical line terminal (OLT) side has been determined when both links use the same wavelength. Bit Error Rate (BER) measurements have been performed with different transmission rates, using several techniques to mitigate the influence of backscattering over the received signal and considering cases with filtered and unfiltered BS.

Study of multi-LLID technology to support multi-services carring in EPONS

NASA Astrophysics Data System (ADS)

Li, Wang; Yi, Benshun; Cheng, Chuanqing

2006-09-01

The Ethernet Passive Optical Network (EPON) has recently attracted more and more research attentions since it could be a perfect candidate for next generation access networks. EPON utilizes pon structure to carry ethernet data, having the both advantages of pon and ethernet devices. From traditional view, EPON is considered to only be a Ethernet services access platform and wake in supporting multi-services especially real-time service. It is obvious that if epon designed only to aim to carrying data service, it is difficult for epon devices to fulfill service provider's command of taking EPON as a integrated service access platform. So discussing the multi-services carrying technology in EPONs is a significative task. This paper deploy a novel method of multi-llid to support multi-services carrying in EPONs.

Factors influencing the characteristics and distribution or surface organic matter in the Pacific-Atlantic connection

NASA Astrophysics Data System (ADS)

Barrera, Facundo; Lara, Rubén J.; Krock, Bernd; Garzón-Cardona, John Edison; Fabro, Elena; Koch, Boris P.

2017-11-01

The present work reports the first data set on particulate organic carbon (POC) and nitrogen (PON), and the high-resolution modelling of their stable isotope variability in the Patagonian Cold Estuarine System (PCES), with focus on particulate organic matter (POM) origin and distribution in dependence on physical, chemical and biological parameters. POC, PON, stable carbon (δ13C) and nitrogen isotopes (δ15N), dissolved organic nitrogen, phaeopigments, diatom, dinoflagellate and heterotrophic bacteria (HB) abundance are reported for 17 stations in different waters masses in the southern end of the Argentine shelf in late summer 2012. Most parameters denote clear differences between Beagle - Magellan Water (BMW), Subantarctic Shelf Water (SSW) and Subantarctic Water (SAW). POC and PON decreased from maxima in BMW to intermediate values in SSW and minima in SAW. There was a highly significant correlation among POC, PON and fluorescence indicators of diagenetic maturity of dissolved humic matter. This, together with the inverse correlations of salinity with POC and PON, and the wide range of C:N ratios indicate that POM in the study area is partly derived from terrestrial runoff, superimposed by autochthonous components from plankton of different life stages. HB abundance was significantly correlated with POC and dissolved organic matter (DOM), likely reflecting a resource control of HB and a significant contribution of bacterial biomass to POM in the nanoparticle fraction. The direct relationship between HB and dissolved humics suggests bacterial uptake of DOM fractions otherwise considered refractory. POM complexity was reflected in a wide variation of δ13C, despite the narrow temperature range of this region. The variability of stable isotopes of POC could be accounted for by a model with a degree of detail hitherto not reported in the literature. A multiple regression including C:N ratio, ammonium and the quotient between log abundance of diatoms, dinoflagellates and HB explained 92% of δ13C variance, mostly produced by ammonium. Despite the strong effect of ammonium on δ13C, δ15N variability was largely explained by a strong inverse relationship with the fraction of unutilized nitrate, suggesting dominance of nitrate uptake. However, the proportion of presumably isotopically heavier ammonium derived from continental runoff in the marine δ15N-POM pool is unknown and requires investigation of the isotopic composition of dissolved inorganic nitrogen in the PCES. The presented new information and its comparison with data from other sectors of the Argentine shelf constitute a contribution to an approach for the understanding of the organic matter dynamics that can be potentially expanded to the entire Southwest Atlantic.

Effect of the Oxidant-Antioxidant System in Seminal Plasma on Varicocele and Idiopathic Infertility in Male Humans.

PubMed

Yazar, Hayrullah; Halis, Fikret; Nasir, Yasemin; Guzel, Derya; Akdogan, Mehmet; Gokce, Ahmet

2017-05-01

The aim of this study was to investigate seminal oxidant-antioxidant activity in idiopathic and varicocele infertility in men. Total anti-oxidant capacity (TAC), total oxidant status (TOS), paraoxonase (PON1), aryl esterase (ARE), and total thiol levels (TTL) were measured in seminal plasma with an autoanalyzer. The TOS/TAC ratio was determined as the oxidative stress index (OSI). A histopathological evaluation of the sperm was performed in the andrology laboratory of the hospital. Number, motility, morphology, volume, pH, and leukocytes were evaluated in all samples according to World Health Organization criteria. The three study groups were as follows: G1, males with idiopathic infertility; G2, males with varicocele infertility; and G3, normal healthy males (had fathered a child in the last 2 years). Each group was composed of 36 men (age, 25 - 40 years). The Rel Assay Diagnostics kit was used to determine the levels of the parameters. The study was conducted according to the principles of the declaration of Helsinki and was approved by Sakarya University Medicine Faculty Ethic Committee (e.n: 16214662/050.01.04/07). Statistical significance was assumed if p < 0.05. All statistical evaluations were performed using SPSS (version 20.0 for Windows; SPSS, Inc., Chicago, IL, USA). No differences were detected between the mean values of antioxidant parameters among the three groups (Kruskal-Wallis test). The p-values of the test parameters (TAC, TOS, PON1, ARE, TTL, OSI) are respectively: 0.494, 0.548, 0.068, 0.151, 0.202, 0.873. The antioxidant parameters of all subjects were compared using the MannWhitney U-test in both groups as fertile (G3) and infertile (G1 + G2). The PON1 levels in infertile subjects were significantly higher than those in fertile subjects. There was a statistically significant difference (p = 0.042). The other antioxidant parameters had no statistically significant difference (p > 0.05). The ARE was not performed in group 3 (control) due to a methodological problem. PON1 levels in infertile subjects were significantly higher than those of fertile subjects.

Acetylcholinesterase, butyrylcholinesterase and paraoxonase 1 activities in rats treated with cannabis, tramadol or both.

PubMed

Abdel-Salam, Omar M E; Youness, Eman R; Khadrawy, Yasser A; Sleem, Amany A

2016-11-01

To investigate the effect of Cannabis sativa resin and/or tramadol, two commonly drugs of abuse on acetylcholinesterase and butyrylcholinesterase activities as a possible cholinergic biomarkers of neurotoxicity induced by these agents. Rats were treated with cannabis resin (5, 10 or 20 mg/kg) (equivalent to the active constituent Δ 9 -tetrahydrocannabinol), tramadol (5, 10 and 20 mg/kg) or tramadol (10 mg/kg) combined with cannabis resin (5, 10 and 20 mg/kg) subcutaneously daily for 6 weeks. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were measured in brain and serum. We also measured the activity of paraoxonase-1 (PON1) in serum of rats treated with these agents. (i) AChE activity in brain increased after 10-20 mg/kg cannabis resin (by 16.3-36.5%). AChE activity in brain did not change after treatment with 5-20 mg/kg tramadol. The administration of both cannabis resin (5, 10 or 20 mg/kg) and tramadol (10 mg/kg) resulted in decreased brain AChE activity by 14.1%, 12.9% and 13.6%, respectively; (ii) BChE activity in serum was markedly and dose-dependently inhibited by cannabis resin (by 60.9-76.9%). BChE activity also decreased by 17.6-36.5% by 10-20 mg/kg tramadol and by 57.2-63.9% by the cannabis resin/tramadol combined treatment; (iii) Cannabis resin at doses of 20 mg/kg increased serum PON1 activity by 25.7%. In contrast, tramadol given at 5, 10 and 20 mg/kg resulted in a dose-dependent decrease in serum PON1 activity by 19%, 36.7%, and 46.1%, respectively. Meanwhile, treatment with cannabis resin plus tramadol resulted in 40.2%, 35.8%, 30.7% inhibition of PON1 activity compared to the saline group. These data suggest that cannabis resin exerts different effects on AChE and BChE activities which could contribute to the memory problems and the decline in cognitive function in chronic users. Copyright © 2016 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Organic forms dominate hydrologic nitrogen export from a lowland tropical watershed.

PubMed

Taylor, Philip G; Wieder, William R; Weintraub, Samantha; Cohen, Sagy; Cleveland, Cory C; Townsend, Alan R

2015-05-01

Observations of high dissolved inorganic nitrogen (DIN) concentrations in stream water have reinforced the notion that primary tropical rain forests cycle nitrogen (N) in relative excess compared to phosphorus. Here we test this notion by evaluating hydrologic N export from a small watershed on the Osa Peninsula, Costa Rica, where prior research has shown multiple indicators of conservative N cycling throughout the ecosystem. We repeatedly measured a host of factors known to influence N export for one year, including stream water chemistry and upslope litterfall, soil N availability and net N processing rates, and soil solution chemistry at the surface, 15- and 50-cm depths. Contrary to prevailing assumptions about the lowland N cycle, we find that dissolved organic nitrogen (DON) averaged 85% of dissolved N export for 48 of 52 consecutive weeks. For most of the year stream water nitrate (NO3-) export was very low, which reflected minimal net N processing and DIN leaching from upslope soils. Yet, for one month in the dry season, NO3- was the major component of N export due to a combination of low flows and upslope nitrification that concentrated NO3- in stream water. Particulate organic N (PON) export was much larger than dissolved forms at 14.6 kg N x ha(-1) x yr(-1), driven by soil erosion during storms. At this rate, PON export was slightly greater than estimated inputs from free-living N fixation and atmospheric N deposition, which suggests that erosion-driven PON export could constrain ecosystem level N stocks over longer timescales. This phenomenon is complimentary to the "DON leak" hypothesis, which postulates that the long-term accumulation of ecosystem N in unpolluted ecosystems is constrained by the export of organic N independently of biological N demand. Using an established global sediment generation model, we illustrate that PON erosion may be an important vector for N loss in tropical landscapes that are geomorphically active. This study supports an emerging view that landscape geomorphology influences nutrient biogeochemistry and limitation, though more research is needed to understand the mechanisms and spatial significance of erosional N loss from terrestrial ecosystems.

Isopropanol alcohol poisoning

MedlinePlus

... VJ, Pons PT, Bakes KM, Buchanan JA, eds. Emergency Medicine Secrets . 6th ed. Philadelphia, PA: Elsevier; 2016:chap ... RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 9th ed. Philadelphia, PA: ...

Effects of weightlessness on neurotransmitter receptors in selected brain areas

NASA Technical Reports Server (NTRS)

Miller, J. D.; Murakami, D. M.; Mcmillen, B. A.; Mcconnaughey, M. M.; Williams, H. L.

1985-01-01

The central nervous system receptor dynamics of rats exposed to 7 days of microgravity are studied. The receptor affinity and receptor number at the hippocampus, lateral frontal cortex, prefrontal cortex, corpus striatum, cerebellum and pons-medulla, and the Na(+)/K(+)ATPase activity are examined. The data reveal that there is no significant change in the receptor affinity and receptor number for the lateral frontal cortex, prefrontal cortex, cerebellum and pons-medulla; however, there is an increase from 81 + or - 11 to 120 + or 5 fmole/mg protein in the receptor number for hippocampal binding, and a decrease in receptor number for the striatum from 172 + or - 14 to 143 + or - 10 fmoles/mg protein. A 9 percent decrease in Mg-dependent Na(+)/K(+)ATPase activity is observed. It is detected that the terminal mechanism may be affected by exposure to microgravity.

OLT-centralized sampling frequency offset compensation scheme for OFDM-PON.

PubMed

Chen, Ming; Zhou, Hui; Zheng, Zhiwei; Deng, Rui; Chen, Qinghui; Peng, Miao; Liu, Cuiwei; He, Jing; Chen, Lin; Tang, Xionggui

2017-08-07

We propose an optical line terminal (OLT)-centralized sampling frequency offset (SFO) compensation scheme for adaptively-modulated OFDM-PON systems. By using the proposed SFO scheme, the phase rotation and inter-symbol interference (ISI) caused by SFOs between OLT and multiple optical network units (ONUs) can be centrally compensated in the OLT, which reduces the complexity of ONUs. Firstly, the optimal fast Fourier transform (FFT) size is identified in the intensity-modulated and direct-detection (IMDD) OFDM system in the presence of SFO. Then, the proposed SFO compensation scheme including phase rotation modulation (PRM) and length-adaptive OFDM frame has been experimentally demonstrated in the downlink transmission of an adaptively modulated optical OFDM with the optimal FFT size. The experimental results show that up to ± 300 ppm SFO can be successfully compensated without introducing any receiver performance penalties.

Design and performance investigation of LDPC-coded upstream transmission systems in IM/DD OFDM-PONs

NASA Astrophysics Data System (ADS)

Gong, Xiaoxue; Guo, Lei; Wu, Jingjing; Ning, Zhaolong

2016-12-01

In Intensity-Modulation Direct-Detection (IM/DD) Orthogonal Frequency Division Multiplexing Passive Optical Networks (OFDM-PONs), aside from Subcarrier-to-Subcarrier Intermixing Interferences (SSII) induced by square-law detection, the same laser frequency for data sending from Optical Network Units (ONUs) results in ONU-to-ONU Beating Interferences (OOBI) at the receiver. To mitigate those interferences, we design a Low-Density Parity Check (LDPC)-coded and spectrum-efficient upstream transmission system. A theoretical channel model is also derived, in order to analyze the detrimental factors influencing system performances. Simulation results demonstrate that the receiver sensitivity is improved 3.4 dB and 2.5 dB under QPSK and 8QAM, respectively, after 100 km Standard Single-Mode Fiber (SSMF) transmission. Furthermore, the spectrum efficiency can be improved by about 50%.

Experimental Evaluation of Energy Efficiency for a Soft Wearable Robotic Suit.

PubMed

Jin, Shanhai; Iwamoto, Noriyasu; Hashimoto, Kazunobu; Yamamoto, Motoji

2016-10-12

This paper presents a new soft wearable robotic suit for energy-efficient walking in daily activities for elderly persons. The presented robotic suit provides a small yet effective assistive force for hip flexion through winding belts that include elastic elements. In addition, it does not restrict the range of movement in the lower limbs. Moreover, its structure is simple and lightweight, and thus wearers can easily take the device on and off by themselves. Experimental results on nine elderly subjects (age = 74.23.7 years) show that the robotic suit worn and powered on (PON) significantly reduced energy expenditure by an average of 5.9 % compared with the condition of worn but powered off (POFF). Furthermore, compared with the POFF condition, there was a significant improvement in gait characteristics in the PON condition for all subjects.

WDM-PON Architecture for FTTx Networks

NASA Astrophysics Data System (ADS)

Iannone, E.; Franco, P.; Santoni, S.

Broadband services for residential users in European countries have until now largely relied on xDSL technologies, while FTTx technologies have been mainly exploited in Asia and North America. The increasing bandwidth demand and the growing penetration of new services are pushing the deployment of optical access networks, and major European operators are now announcing FTTx projects. While FTTH is recognized as the target solution to bring broadband services to residential users, the identification of an FTTx evolutionary path able to seamlessly migrate to FTTH is key to enabling a massive deployment, easing the huge investments needed. WDM-PON architecture is an interesting solution that is able to accommodate the strategic need of building a new fiber-based access infrastructure with the possibility of adapting investments to actual demands and evolving to FTTH without requiring further interventions on fiber infrastructures.

Simultaneous wavelength and format conversion in SDN/NFV for flexible optical network based on FWM in SOA

NASA Astrophysics Data System (ADS)

Zhan, Yueying; Wang, Danshi; Zhang, Min

2018-04-01

We propose an all-optical wavelength and format conversion model (CM) for a dynamic data center interconnect node and coherent passive optical network (PON) optical network unit (ONU) in software-defined networking and network function virtualization system based on four-wave mixing in a semiconductor optical amplifier. Five wavelength converted DQPSK signals and two format converted DPSK signals are generated; the performances of the generated signals for two strategies of setting CM in the data center interconnect node and coherent PON ONU, which are over 10 km fiber transmission, have been verified. All of the converted signals are with a power penalty less than 2.2 dB at FEC threshold of 3.8 × 10 - 3, and the optimum bias current of SOA is 300 mA.

Citric acid effects on brain and liver oxidative stress in lipopolysaccharide-treated mice.

PubMed

Abdel-Salam, Omar M E; Youness, Eman R; Mohammed, Nadia A; Morsy, Safaa M Youssef; Omara, Enayat A; Sleem, Amany A

2014-05-01

Citric acid is a weak organic acid found in the greatest amounts in citrus fruits. This study examined the effect of citric acid on endotoxin-induced oxidative stress of the brain and liver. Mice were challenged with a single intraperitoneal dose of lipopolysaccharide (LPS; 200 μg/kg). Citric acid was given orally at 1, 2, or 4 g/kg at time of endotoxin injection and mice were euthanized 4 h later. LPS induced oxidative stress in the brain and liver tissue, resulting in marked increase in lipid peroxidation (malondialdehyde [MDA]) and nitrite, while significantly decreasing reduced glutathione, glutathione peroxidase (GPx), and paraoxonase 1 (PON1) activity. Tumor necrosis factor-alpha (TNF-α) showed a pronounced increase in brain tissue after endotoxin injection. The administration of citric acid (1-2 g/kg) attenuated LPS-induced elevations in brain MDA, nitrite, TNF-α, GPx, and PON1 activity. In the liver, nitrite was decreased by 1 g/kg citric acid. GPx activity was increased, while PON1 activity was decreased by citric acid. The LPS-induced liver injury, DNA fragmentation, serum transaminase elevations, caspase-3, and inducible nitric oxide synthase expression were attenuated by 1-2 g/kg citric acid. DNA fragmentation, however, increased after 4 g/kg citric acid. Thus in this model of systemic inflammation, citric acid (1-2 g/kg) decreased brain lipid peroxidation and inflammation, liver damage, and DNA fragmentation.

Citric Acid Effects on Brain and Liver Oxidative Stress in Lipopolysaccharide-Treated Mice

PubMed Central

Youness, Eman R.; Mohammed, Nadia A.; Morsy, Safaa M. Youssef; Omara, Enayat A.; Sleem, Amany A.

2014-01-01

Abstract Citric acid is a weak organic acid found in the greatest amounts in citrus fruits. This study examined the effect of citric acid on endotoxin-induced oxidative stress of the brain and liver. Mice were challenged with a single intraperitoneal dose of lipopolysaccharide (LPS; 200 μg/kg). Citric acid was given orally at 1, 2, or 4 g/kg at time of endotoxin injection and mice were euthanized 4 h later. LPS induced oxidative stress in the brain and liver tissue, resulting in marked increase in lipid peroxidation (malondialdehyde [MDA]) and nitrite, while significantly decreasing reduced glutathione, glutathione peroxidase (GPx), and paraoxonase 1 (PON1) activity. Tumor necrosis factor-alpha (TNF-α) showed a pronounced increase in brain tissue after endotoxin injection. The administration of citric acid (1–2 g/kg) attenuated LPS-induced elevations in brain MDA, nitrite, TNF-α, GPx, and PON1 activity. In the liver, nitrite was decreased by 1 g/kg citric acid. GPx activity was increased, while PON1 activity was decreased by citric acid. The LPS-induced liver injury, DNA fragmentation, serum transaminase elevations, caspase-3, and inducible nitric oxide synthase expression were attenuated by 1–2 g/kg citric acid. DNA fragmentation, however, increased after 4 g/kg citric acid. Thus in this model of systemic inflammation, citric acid (1–2 g/kg) decreased brain lipid peroxidation and inflammation, liver damage, and DNA fragmentation. PMID:24433072

Upstream capacity upgrade in TDM-PON using RSOA based tunable fiber ring laser.

PubMed

Yi, Lilin; Li, Zhengxuan; Dong, Yi; Xiao, Shilin; Chen, Jian; Hu, Weisheng

2012-04-23

An upstream multi-wavelength shared (UMWS) time division multiplexing passive optical network (TDM-PON) is presented by using a reflective semiconductor amplifier (RSOA) and tunable optical filter (TOF) based directly modulated fiber ring laser as upstream laser source. The stable laser operation is easily achieved no matter what the bandwidth and shape of the TOF is and it can be directly modulated when the RSOA is driven at its saturation region. In this UMWS TDM-PON system, an individual wavelength can be assigned to the user who has a high bandwidth demand by tuning the central wavelength of the TOF in its upgraded optical network unit (ONU), while others maintain their traditional ONU structure and share the bandwidth via time slots, which greatly and dynamically upgrades the upstream capacity. We experimentally demonstrated the bidirectional transmission of downstream data at 10-Gb/s and upstream data at 1.25-Gb/s per wavelength over 25-km single mode fiber (SMF) with almost no power penalty at both ends. A stable performance is observed for the upstream wavelength tuned from 1530 nm to 1595 nm. Moreover, due to the high extinction ratio (ER) of the upstream signal, the burst-mode transmitting is successfully presented and a better time-division multiplexing performance can be obtained by turning off the unused lasers thanks to the rapid formation of the laser in the fiber ring. © 2012 Optical Society of America

In Situ STEM-EELS observation of nanoscale interfacial phenomena in all-solid-state batteries

DOE PAGES

Wang, Ziying; Santhanagopalan, Dhamodaran; Zhang, Wei; ...

2016-05-03

Behaviors of functional interfaces are crucial factors in the performance and safety of energy storage and conversion devices. Indeed, solid electrode–solid electrolyte interfacial impedance is now considered the main limiting factor in all-solid-state batteries rather than low ionic conductivity of the solid electrolyte. In this paper, we present a new approach to conducting in situ scanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS) in order to uncover the unique interfacial phenomena related to lithium ion transport and its corresponding charge transfer. Our approach allowed quantitative spectroscopic characterization of a galvanostatically biased electrochemical system under in situmore » conditions. Using a LiCoO 2/LiPON/Si thin film battery, an unexpected structurally disordered interfacial layer between LiCoO 2 cathode and LiPON electrolyte was discovered to be inherent to this interface without cycling. During in situ charging, spectroscopic characterization revealed that this interfacial layer evolved to form highly oxidized Co ions species along with lithium oxide and lithium peroxide species. These findings suggest that the mechanism of interfacial impedance at the LiCoO 2/LiPON interface is caused by chemical changes rather than space charge effects. Finally, insights gained from this technique will shed light on important challenges of interfaces in all-solid-state energy storage and conversion systems and facilitate improved engineering of devices operated far from equilibrium.« less

Evaluation of oxidative stress status and antioxidant capacity in patients with renal cell carcinoma

PubMed Central

Karaguzel, Ersagun; Okulu, Emrah; Gudeloglu, Ahmet; Ener, Kemal; Ozayar, Asim; Erel, Ozcan

2015-01-01

Introduction We evaluated and compared the serum oxidative stress and antioxidant enzymes in patients with renal cell carcinoma (RCC) and the control group. Material and methods The prospective study consisted of 97 patients with RCC (Group 1) and 80 age and sex matched healthy volunteers (Group 2). Group 1 and 2 were compared concerning serum mean total oxidant status (TOS), total antioxidant capacity (TAC), paraoxonase-1 (PON-1), arylesterase, total thiol, catalase (CAT), myeloperoxidase (MPO) and ceruloplasmin. Results Patients’ mean age was 58.5 ±12.3 and 56.9 ±15.8 years, respectively, in Group 1 and 2. No statistically significant differences were detected between the groups in terms of oxidative stress parameters and antioxidant capacity measured in the serum of patients including, TOS, TAC, PON1, arylesterase, total thiol, CAT, MPO, and ceruloplasmin levels (p >0.05 for all parameters). The PON-1 value was significantly higher in patients with pT1 stage than pT3 stage (p = 0.007). The arylesterase value was significantly higher in patients with Fuhrman's nuclear grade 3 than grade 2 (p = 0.035). There was no correlation between these parameters level and Fuhrman's nuclear grade, stage, or histopathological tumor type. Conclusions Our results demonstrated that evaluation of these parameters in the serum of patients with localized RCC may not be used as a marker to discriminate between patients with RCC and healthy people. PMID:26855793

Altered inflammation, paraoxonase-1 activity and HDL physicochemical properties in obese humans with and without Prader-Willi syndrome

PubMed Central

Ferretti, Gianna; Bacchetti, Tiziana; Masciangelo, Simona; Grugni, Graziano; Bicchiega, Virginia

2012-01-01

SUMMARY Prader-Willi syndrome (PWS) represents the most common form of genetic obesity. Several studies confirm that obesity is associated with inflammation, oxidative stress and impairment of antioxidant systems; however, no data are available concerning PWS subjects. We compared levels of plasma lipids and C-reactive protein (CRP) in 30 subjects of ‘normal’ weight (18.5–25 kg/m2), 15 PWS obese (>30 kg/m2) subjects and 13 body mass index (BMI)-matched obese subjects not affected by PWS. In all subjects, we evaluated the levels of lipid hydroperoxides and the activity of paraoxonase-1 (PON1), an enzyme involved in the antioxidant and anti-inflammatory properties exerted by high-density lipoproteins (HDLs). Furthermore, using the fluorescent molecule of Laurdan, we investigated the physicochemical properties of HDLs isolated from normal weight and obese individuals. Altogether, our results demonstrated, for the first time, higher levels of lipid hydroperoxides and a lower PON1 activity in plasma of obese individuals with PWS with respect to normal-weight controls. These alterations are related to CRP levels, with a lower PON1:CRP ratio in PWS compared with non-PWS obese subjects. The study of Laurdan fluorescence parameters showed significant modifications of physicochemical properties in HDLs from PWS individuals. Whatever the cause of obesity, the increase of adiposity is associated with inflammation, oxidative stress and alterations in HDL compositional and functional properties. PMID:22822045

An Age-Dependent Physiologically-Based Pharmacokinetic/Pharmacodynamic Model for the Organophosphorus Insecticide Chlorpyrifos in the Preweanling Rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timchalk, Chuck; Kousba, Ahmed A.; Poet, Torka S.

2007-08-01

Juvenile rats are more susceptible than adults to the acute toxicity of organophosphorus insecticides like chlorpyrifos (CPF). Age- and dose-dependent differences in metabolism may be responsible. Of importance is CYP450 activation and detoxification of CPF to chlorpyrifos-oxon (CPF-oxon) and trichloropyridinol (TCP), as well as B-esterase (cholinesterase; ChE) and A-esterase (PON-1) detoxification of CPF-oxon to TCP. In the current study, a modified physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model incorporating age-dependent changes in CYP450, PON-1, and tissue ChE levels for rats was developed. In this model, age was used as a dependent function to estimate body weight which was then used to allometricallymore » scale both metabolism and tissue ChE levels. Model simulations suggest that preweanling rats are particularly sensitive to CPF toxicity, with levels of CPF-oxon in blood and brain disproportionately increasing, relative to the response in adult rats. This age-dependent non-linear increase in CPF-oxon concentration may potentially result from the depletion of non-target B-esterases, and a lower PON-1 metabolic capacity in younger animals. These results indicate that the PBPK/PD model behaves consistently with the general understanding of CPF toxicity, pharmacokinetics and tissue ChE inhibition in neonatal and adult rats. Hence, this model represents an important starting point for developing a computational model to assess the neurotoxic potential of environmentally relevant organophosphate exposures in infants and children.« less

Experimental demonstration of a 16.9 Gb/s link for coherent OFDM PON robust to frequency offset and timing error

NASA Astrophysics Data System (ADS)

Ma, Qian; Liu, Yu; Xiang, Yuanjiang

2018-07-01

Due to its merits of flexible bandwidth allocation and robustness towards fiber transmission impairments, coherent optical orthogonal frequency division multiplexing (CO-OFDM) technology draws a lot of attention for passive optical networks (PON). However, a CO-OFDM system is vulnerable to frequency offsets between modulated optical signals and optical local oscillators (OLO). This is particularly serious for low cost PONs where low cost lasers are used. Thus, it is of great interest to develop efficient algorithms for frequency synchronization in CO-OFDM systems. Usually frequency synchronization proposed in CO-OFDM systems are done by detecting the phase shift in time domain. In such a way, there is a trade-off between estimation accuracy and range. Considering that the integer frequency offset (IFO) contributes to the major frequency offset, a more efficient method to estimate IFO is of demand. By detecting IFO induced circular channel rotation (CCR), the frequency offset can be directly estimated after fast Fourier transforming (FFT). In this paper, circular acquisition offset frequency and timing synchronization (CAO-FTS) scheme is proposed. A specially-designed frequency domain pseudo noise (PN) sequence is used for CCR detection and timing synchronization. Full-range frequency offset compensation and non-plateau timing synchronization are experimentally demonstrated in presence of fiber dispersion. Based on CAO-FTS, 16.9 Gb/s CO-OFDM signal is successfully delivered over a span of 80-km single mode fiber.

Alteration of the Expression of Pesticide-Metabolizing Enzymes in Pregnant Mice: Potential Role in the Increased Vulnerability of the Developing Brain

PubMed Central

Fortin, Marie C.; Aleksunes, Lauren M.

2013-01-01

Studies on therapeutic drug disposition in humans have shown significant alterations as the result of pregnancy. However, it is not known whether pesticide metabolic capacity changes throughout pregnancy, which could affect exposure of the developing brain. We sought to determine the effect of pregnancy on the expression of hepatic enzymes involved in the metabolism of pesticides. Livers were collected from virgin and pregnant C57BL/6 mice at gestational days (GD)7, GD11, GD14, GD17, and postpartum days (PD)1, PD15, and PD30. Relative mRNA expression of several enzymes involved in the metabolism of pesticides, including hepatic cytochromes (Cyp) P450s, carboxylesterases (Ces), and paraoxonase 1 (Pon1), were assessed in mice during gestation and the postpartum period. Compared with virgin mice, alterations in the expression occurred at multiple time points, with the largest changes observed on GD14. At this time point, the expression of most of the Cyps involved in pesticide metabolism in the liver (Cyp1a2, Cyp2d22, Cyp2c37, Cyp2c50, Cyp2c54, and Cyp3a11) were downregulated by 30% or more. Expression of various Ces isoforms and Pon1 were also decreased along with Pon1 activity. These data demonstrate significant alterations in the expression of key enzymes that detoxify pesticides during pregnancy, which could alter exposure of developing animals to these chemicals. PMID:23223497

Progress of MCT Detector Technology at AIM Towards Smaller Pitch and Lower Dark Current

NASA Astrophysics Data System (ADS)

Eich, D.; Schirmacher, W.; Hanna, S.; Mahlein, K. M.; Fries, P.; Figgemeier, H.

2017-09-01

We present our latest results on cooled p-on- n planar mercury cadmium telluride (MCT) photodiode technology. Along with a reduction in dark current for raising the operating temperature ( T op), AIM INFRAROT-MODULE GmbH (AIM) has devoted its development efforts to shrinking the pixel size. Both are essential requirements to meet the market demands for reduced size, weight and power and high-operating temperature applications. Detectors based on the p-on- n technology developed at AIM now span the spectrum from the mid-wavelength infrared (MWIR) to the very long wavelength infrared (VLWIR) with cut-off wavelengths from 5 μm to about 13.5 μm at 80 K. The development of the p-on- n technology for VLWIR as well as for MWIR is mainly implemented in a planar photodetector design with a 20- μm pixel pitch. For the VLWIR, dark currents significantly reduced as compared to `Tennant's Rule 07' are demonstrated for operating temperatures between 30 K and 100 K. This allows for the same dark current performance at a 20 K higher operating temperature than with previous AIM technology. For MWIR detectors with a 20- μm pitch, noise equivalent temperature differences of less than 30 mK are obtained up to 170 K. This technology has been transferred to our small pixel pitch high resolution (XGA) MWIR detector with 1024 × 768 pixels at a 10- μm pitch. Excellent performance at an operating temperature of 160 K is demonstrated.

Fault detection technique for wavelength division multiplexing passive optical network using chaotic fiber laser

NASA Astrophysics Data System (ADS)

Xu, Naijun; Yang, Lingzhen; Zhang, Juan; Zhang, Xiangyuan; Wang, Juanfen; Zhang, Zhaoxia; Liu, Xianglian

2014-03-01

We propose a fault localization method for wavelength division multiplexing passive optical network (WDM-PON). A proof-of-concept experiment was demonstrated by utilizing the wavelength tunable chaotic laser generated from an erbium-doped fiber ring laser with a manual tunable fiber Bragg grating (TFBG) filter. The range of the chaotic lasing wavelength can cover the C-band. Basing on the TFBG filter, we can adjust the wavelength of the chaotic laser to match the WDM-PON channel with identical wavelength. We determined the fault location by calculating the cross-correlation between the reference and return signals. Analysis of the characteristics of the wavelength tunable chaotic laser showed that the breakpoint, the loose connector, and the mismatch connector could be precisely located. A dynamic range of approximately 23.8 dB and a spatial resolution of 4 cm, which was independent of the measuring range, were obtained.

300 Gb/s IM/DD based SDM-WDM-PON with laserless ONUs.

PubMed

Bao, Fangdi; Morioka, Toshio; Oxenløwe, Leif K; Hu, Hao

2018-04-02

A low-cost, high-speed SDM-WDM-PON architecture is proposed by using a multi-core fiber (MCF) and intensity modulation/directly detection (IM/DD). One of the MCF cores is used for sending laser sources from optical line terminal (OLT) to optical network unit (ONU), thus facilitating laserless and colorless ONUs, and providing ease of network management and maintenance. In addition, the wavelengths of the ONUs are controlled on the OLT side, which also enables flexible optical networks. Thanks to the low inter-core crosstalk of a MCF, downstream (DS) and upstream (US) signals are transmitted independently in different cores of the MCF, not only increasing the aggregated capacity but also avoiding the Rayleigh backscattering noise. Finally, a proof-of-principle experiment is performed by using a 7-core fiber, achieving 300 /120 Gb/s aggregated capacity for DS and US (3 × cores, 4 × wavelengths, 25/10 Gb/s per wavelength), respectively.

The intermediate comets and nongravitational effects

NASA Technical Reports Server (NTRS)

Yeomans, D. K.

1986-01-01

The motions of the intermediate-period comets Pons-Brooks, Olbers, Brorsen-Metcalf, and Westphal are investigated over their observed intervals. The three apparitions of comets Pons-Brooks and Olbers were successfully linked, using the now standard nongravitational-force model. The two apparitions of Comet Brorsen-Metcalf were successfully linked without the need for nongravitational effects. For the 1852 and 1913 apparitions of Comet Westphal, complete success was not achieved in modeling the comet's motion either with or without nongravitational effects. However, by including these effects, the comet's astrometric observations could be represented significantly better than if they were assumed inoperative. Comet Westphal's dynamic and photometric behavior suggests its complete disintegration before reaching perihelion in 1913. If the very large radial nongravitational parameter determined for Comet Westphal is due to the comet's disintegration into dust, then the resultant dust-particle size is of the order of 0.8 mm.

Low-Cost WDM-PON With Colorless Bidirectional Transceivers

NASA Astrophysics Data System (ADS)

Shin, Dong Jae; Keh, Y. C.; Kwon, J. W.; Lee, E. H.; Lee, J. K.; Park, M. K.; Park, J. W.; Oh, Y. K.; Kim, S. W.; Yun, I. K.; Shin, H. C.; Heo, D.; Lee, J. S.; Shin, H. S.; Kim, H. S.; Park, S. B.; Jung, D. K.; Hwang, Seongtaek; Oh, Y. J.; Jang, D. H.; Shim, C. S.

2006-01-01

This paper presents a low-cost bidirectional (BiDi) wavelength-division-multiplexed passive optical network (WDM-PON) employing colorless uncooled BiDi transceivers (TRxs) and superluminescent diode (SLD)-based broadband light sources (BLSs). The C band is allocated for upstream and the E+ band for downstream in consideration of BiDi packaging, SLD development, and wavelength alignment of dual-window arrayed waveguide gratings (AWGs). The BiDi TRx integrates an uncooled Fabry-Pérot laser diode (FP-LD), a p-i-n photodiode (PD), and a 45°-angled thin-film filter in a small-form-factor (SFF) package. The SLD-based BLSs provide 13-dBm amplified spontaneous emissions (ASEs) with spectral ripples of < 3 dB and polarization dependencies of < 1 dB. Colorless operations over 32 100-GHz-spaced channels are demonstrated from -20 to 80°C in 155-Mb/s BiDi transmissions over 25 km.

Dynamic bandwidth allocation based on multiservice in software-defined wavelength-division multiplexing time-division multiplexing passive optical network

NASA Astrophysics Data System (ADS)

Wang, Fu; Liu, Bo; Zhang, Lijia; Jin, Feifei; Zhang, Qi; Tian, Qinghua; Tian, Feng; Rao, Lan; Xin, Xiangjun

2017-03-01

The wavelength-division multiplexing passive optical network (WDM-PON) is a potential technology to carry multiple services in an optical access network. However, it has the disadvantages of high cost and an immature technique for users. A software-defined WDM/time-division multiplexing PON was proposed to meet the requirements of high bandwidth, high performance, and multiple services. A reasonable and effective uplink dynamic bandwidth allocation algorithm was proposed. A controller with dynamic wavelength and slot assignment was introduced, and a different optical dynamic bandwidth management strategy was formulated flexibly for services of different priorities according to the network loading. The simulation compares the proposed algorithm with the interleaved polling with adaptive cycle time algorithm. The algorithm shows better performance in average delay, throughput, and bandwidth utilization. The results show that the delay is reduced to 62% and the throughput is improved by 35%.

Sleep Neurobiology from a Clinical Perspective

PubMed Central

España, Rodrigo A.; Scammell, Thomas E.

2011-01-01

Many neurochemical systems interact to generate wakefulness and sleep. Wakefulness is promoted by neurons in the pons, midbrain, and posterior hypothalamus that produce acetylcholine, norepinephrine, dopamine, serotonin, histamine, and orexin/hypocretin. Most of these ascending arousal systems diffusely activate the cortex and other forebrain targets. NREM sleep is mainly driven by neurons in the preoptic area that inhibit the ascending arousal systems, while REM sleep is regulated primarily by neurons in the pons, with additional influence arising in the hypothalamus. Mutual inhibition between these wake- and sleep-regulating regions likely helps generate full wakefulness and sleep with rapid transitions between states. This up-to-date review of these systems should allow clinicians and researchers to better understand the effects of drugs, lesions, and neurologic disease on sleep and wakefulness. Citation: España RA; Scammell TE. Sleep neurobiology from a clinical perspective. SLEEP 2011;34(7):845-858. PMID:21731134

Novel WRM-based architecture of hybrid PON featuring online access and full-fiber-fault protection for smart grid

NASA Astrophysics Data System (ADS)

Li, Xingfeng; Gan, Chaoqin; Liu, Zongkang; Yan, Yuqi; Qiao, HuBao

2018-01-01

In this paper, a novel architecture of hybrid PON for smart grid is proposed by introducing a wavelength-routing module (WRM). By using conventional optical passive components, a WRM with M ports is designed. The symmetry and passivity of the WRM makes it be easily integrated and very cheap in practice. Via the WRM, two types of network based on different ONU-interconnected manner can realize online access. Depending on optical switches and interconnecting fibers, full-fiber-fault protection and dynamic bandwidth allocation are realized in these networks. With the help of amplitude modulation, DPSK modulation and RSOA technology, wavelength triple-reuse is achieved. By means of injecting signals into left and right branches in access ring simultaneously, the transmission delay is decreased. Finally, the performance analysis and simulation of the network verifies the feasibility of the proposed architecture.

40-Gb/s PAM4 with low-complexity equalizers for next-generation PON systems

NASA Astrophysics Data System (ADS)

Tang, Xizi; Zhou, Ji; Guo, Mengqi; Qi, Jia; Hu, Fan; Qiao, Yaojun; Lu, Yueming

2018-01-01

In this paper, we demonstrate 40-Gb/s four-level pulse amplitude modulation (PAM4) transmission with 10 GHz devices and low-complexity equalizers for next-generation passive optical network (PON) systems. Simple feed-forward equalizer (FFE) and decision feedback equalizer (DFE) enable 20 km fiber transmission while high-complexity Volterra algorithm in combination with FFE and DFE can extend the transmission distance to 40 km. A simplified Volterra algorithm is proposed for reducing computational complexity. Simulation results show that the simplified Volterra algorithm reduces up to ∼75% computational complexity at a relatively low cost of only 0.4 dB power budget. At a forward error correction (FEC) threshold of 10-3 , we achieve 31.2 dB and 30.8 dB power budget over 40 km fiber transmission using traditional FFE-DFE-Volterra and our simplified FFE-DFE-Volterra, respectively.

PAM4 based symmetrical 112-Gbps long-reach TWDM-PON

NASA Astrophysics Data System (ADS)

Wu, Liyu; Gao, Fan; Zhang, Minming; Fu, Songnian; Deng, Lei; Choi, Michael; Chang, Donald; Lei, Gordon K. P.; Liu, Deming

2018-02-01

We experimentally demonstrate cost effective symmetrical 112-Gbps long-reach passive optical network (LR-PON) over 70-km standard signal mode fiber (SSMF), based on pulse amplitude modulation (PAM)-4. Four 10G-class directly modulated lasers (DMLs) at C-band are used for achieving 4 × 28-Gbps downstream transmission, while two 18G-class DMLs at O-band are used to realize 2 × 56-Gbps upstream transmission, without any optical amplification in optical distributed network (ODN). Both dispersion compensation fiber (DCF) for downstream signal and praseodymium-doped fiber amplifier (PDFA) for upstream signal are equipped at optical line terminal (OLT). Meanwhile, sparse Volterra filter (SVF) equalizer is proposed to mitigate the transmission impairments with substantial reduction of computation complexity. Finally, we can successfully provide a loss budget of 33 dB per downstream wavelength channel, indicating of 64 optical network units (ONUs) with more than 1.25 Gbps per ONU.

Bandwidth efficient bidirectional 5 Gb/s overlapped-SCM WDM PON with electronic equalization and forward-error correction.

PubMed

Buset, Jonathan M; El-Sahn, Ziad A; Plant, David V

2012-06-18

We demonstrate an improved overlapped-subcarrier multiplexed (O-SCM) WDM PON architecture transmitting over a single feeder using cost sensitive intensity modulation/direct detection transceivers, data re-modulation and simple electronics. Incorporating electronic equalization and Reed-Solomon forward-error correction codes helps to overcome the bandwidth limitation of a remotely seeded reflective semiconductor optical amplifier (RSOA)-based ONU transmitter. The O-SCM architecture yields greater spectral efficiency and higher bit rates than many other SCM techniques while maintaining resilience to upstream impairments. We demonstrate full-duplex 5 Gb/s transmission over 20 km and analyze BER performance as a function of transmitted and received power. The architecture provides flexibility to network operators by relaxing common design constraints and enabling full-duplex operation at BER ∼ 10(-10) over a wide range of OLT launch powers from 3.5 to 8 dBm.

Design of the frame structure for a multiservice interactive system using ATM-PON

NASA Astrophysics Data System (ADS)

Nam, Jae-Hyun; Jang, Jongwook; Lee, Jung-Tae

1998-10-01

The MAC (Medium Access Control) protocol controls B-NT1s' (Optical Network Unit) access to the shared capacity on the PON, this protocol is very important if TDMA (Time Division Multiple Access) multiplexing is used on the upstream. To control the upstream traffic some kind of access protocol has to be implemented. There are roughly two different approaches to use request cells: in a collision free way or such that collisions in a request slot are allowed. It is the objective of this paper to describe a MAC-protocol structure that supports both approaches and hybrids of it. In our paper we grantee the QoS (Quality of Service) of each B-NT1 through LOC, LOV, LOA field that are the length field of the transmitted cell at each B-NT1. Each B-NT1 transmits its status of request on request cell.

Broadband Optical Access Technologies to Converge towards a Broadband Society in Europe

NASA Astrophysics Data System (ADS)

Coudreuse, Jean-Pierre; Pautonnier, Sophie; Lavillonnière, Eric; Didierjean, Sylvain; Hilt, Benoît; Kida, Toshimichi; Oshima, Kazuyoshi

This paper provides insights on the status of broadband optical access market and technologies in Europe and on the expected trends for the next generation optical access networks. The final target for most operators, cities or any other player is of course FTTH (Fibre To The Home) deployment although we can expect intermediate steps with copper or wireless technologies. Among the two candidate architectures for FTTH, PON (Passive Optical Network) is by far the most attractive and cost effective solution. We also demonstrate that Ethernet based optical access network is very adequate to all-IP networks without any incidence on the level of quality of service. Finally, we provide feedback from a FTTH pilot network in Colmar (France) based on Gigabit Ethernet PON technology. The interest of this pilot lies on the level of functionality required for broadband optical access networks but also on the development of new home network configurations.

Cholinesterase inhibitor soman increases inositol trisphosphate in rat brain. (Reannouncement with new availability information)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mobley, P.L.

1990-12-31

Studies were conducted to determine the effect of the cholinesterase inhibitor soman on the amount of inositol trisphosphate in the neocortex, striatum, cerebellum, and medulla-pons regions of rat brain in vivo. The studies indicate that treatment with soman increase inositol trisphosphate in the neocortex and striatum, but not in the cerebellum or medulla-pons region. In the neocortex the most pronounced increases were observed in animals with severe poisoning symptoms; however, inositol trisphophate was also found to be elevated in animals with only mild poisoning symptoms. A variety of evidence suggests that the receptor-mediated hydrolysis of phosphatidyl inositol results in themore » formation of inositol trisphosphate (IP3) and diacylglycerol, both of which function as intracellular signal messengers, and that this mechanism represents a major signal transduction system through which extracellular signals can influence intracellular events.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ziying; Lee, Jungwoo Z.; Xin, Huolin L.

All-solid-state lithium-ion batteries have the potential to not only push the current limits of energy density by utilizing Li metal, but also improve safety by avoiding flammable organic electrolyte. However, understanding the role of solid electrolyte – electrode interfaces will be critical to improve performance. In this paper, we conducted long term cycling on commercially available lithium cobalt oxide (LCO)/lithium phosphorus oxynitride (LiPON)/lithium (Li) cells at elevated temperature to investigate the interfacial phenomena that lead to capacity decay. STEM-EELS analysis of samples revealed a previously unreported disordered layer between the LCO cathode and LiPON electrolyte. This electrochemically inactive layer grewmore » in thickness leading to loss of capacity and increase of interfacial resistance when cycled at 80 °C. Finally, the stabilization of this layer through interfacial engineering is crucial to improve the long term performance of thin-film batteries especially under thermal stress.« less

Mapping of somatostatin-28 (1-12) in the alpaca (Lama pacos) brainstem.

PubMed

De Souza, Eliana; Sánchez, Manuel Lisardo; Aguilar, Luís Ángel; Díaz-Cabiale, Zaida; Narváez, José Ángel; Coveñas, Rafael

2015-05-01

Using an indirect immunoperoxidase technique, we studied the distribution of cell bodies and fibers containing somatostatin-28 (1-12) in the alpaca brainstem. Immunoreactive fibers were widely distributed throughout the whole brainstem: 34 brainstem nuclei/regions showed a high or a moderate density of these fibers. Perikarya containing the peptide were widely distributed throughout the mesencephalon, pons and medulla oblongata. Cell bodies containing somatostatin-28 (1-12) were observed in the lateral and medial divisions of the marginal nucleus of the brachium conjunctivum, reticular formation (mesencephalon, pons and medulla oblongata), inferior colliculus, periaqueductal gray, superior colliculus, pericentral division of the dorsal tegmental nucleus, interpeduncular nucleus, nucleus of the trapezoid body, vestibular nucleus, motor dorsal nucleus of the vagus, nucleus of the solitary tract, nucleus praepositus hypoglossi, and in the substantia nigra. This widespread distribution indicates that somatostatin-28 (1-12) is involved in multiple physiological actions in the alpaca brainstem. © 2015 Wiley Periodicals, Inc.

The effect of aromatherapy on postoperative nausea in women undergoing surgical procedures.

PubMed

Ferruggiari, Luisa; Ragione, Barbara; Rich, Ellen R; Lock, Kathleen

2012-08-01

Postoperative nausea and vomiting (PONV) is a common source of patient discomfort and decreased satisfaction. Aromatherapy has been identified as a complementary modality for the prevention and management of PONV. The purpose of this study was to assess the effect of aromatherapy on the severity of postoperative nausea (PON) in women undergoing surgical procedures in the postanesthesia care unit. Women complaining of PON received traditional antiemetics, inhalation of peppermint oil, or saline vapor. A visual analog scale was used to rate nausea at the first complaint; at 5 minutes after intervention; and, if nausea persisted, at 10 minutes after intervention. At both 5 and 10 minutes, statistical analysis showed no significant differences between intervention and nausea rating. Obtaining eligible subjects was challenging. Although many women consented, most received intraoperative antiemetics and did not report nausea postoperatively. Copyright © 2012 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

MRI-Based Measurement of Brain Stem Cross-Sectional Area in Relapsing-Remitting Multiple Sclerosis.

PubMed

Chivers, Tomos R; Constantinescu, Cris S; Tench, Christopher R

2015-01-01

To determine if patients with relapsing-remitting multiple sclerosis (RRMS) have a reduced brain stem cross-sectional area (CSA) compared to age- and sex-matched controls. The brain stem is a common site of involvement in MS. However, relatively few imaging studies have investigated brain stem atrophy. Brain magnetic resonance imaging (MRI) was performed on patients and controls using a 1.5T MRI scanner with a quadrature head coil. Three-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) images with 128 contiguous slices, covering the whole brain and brain stem and a T2-weighted image with 3 mm transverse contiguous images were acquired. We measured the brain stem CSA at three sites, the midbrain, the pons, and the medulla oblongata in 35 RRMS patients and 35 controls using a semiautomated algorithm. CSA readings were normalized using the total external cranial volume to reduce normal population variance and increase statistical power. A significant CSA reduction was found in the midbrain (P ≤ .001), pons (P ≤ .001), and the medulla oblongata (P = .047) postnormalization. A CSA reduction of 9.3% was found in the midbrain, 8.7% in the pons, and 6.5% in the medulla oblongata. A significantly reduced, normalized brain stem CSA was detected in all areas of the brain stem of the RRMS patients, when compared to age- and gender-matched controls. Lack of detectable upper cervical cord atrophy in the same patients suggests some independence of the MS pathology in these regions. Copyright © 2015 by the American Society of Neuroimaging.

Novel toggle-rate based energy-efficient scheme for heavy load real-time IM-DD OFDM-PON with ONU LLID identification in time-domain using amplitude decision.

PubMed

Qin, Youxiang; Zhang, Junjie

2017-07-10

A novel low complexity and energy-efficient scheme by controlling the toggle-rate of ONU with time-domain amplitude identification is proposed for a heavy load downlink in an intensity-modulation and direct-detection orthogonal frequency division multiplexing passive optical network (IM-DD OFDM-PON). In a conventional OFDM-PON downlink, all ONUs have to perform demodulation for all the OFDM frames in a broadcast way no matter whether the frames are targeted to or not, which causes a huge energy waste. However, in our scheme, the optical network unit (ONU) logical link identifications (LLIDs) are inserted into each downlink OFDM frame in time-domain at the optical line terminal (OLT) side. At the ONU side, the LLID is obtained with a low complexity and high precision amplitude identification method. The ONU sets the toggle-rate of demodulation module to zero when the frames are not targeted to, which avoids unnecessary digital signal processing (DSP) energy consumption. Compared with the sleep-mode methods consisting of clock recovery and synchronization, toggle-rate shows its advantage in fast changing, which is more suitable for the heavy load scenarios. Moreover, for the first time to our knowledge, the characteristics of the proposed scheme are investigated in a real-time IM-DD OFDM system, which performs well at the received optical power as low as -21dBm. The experimental results show that 25.1% energy consumption can be saved in the receiver compared to the conventional configurations.

Magnetic properties of the remagnetized Middle-Ordovician limestones of the Ponón Trehué Formation (San Rafael Block, central-western Argentina): Insights into the Permian widespread Sanrafaelic overprint

NASA Astrophysics Data System (ADS)

Fazzito, Sabrina Y.; Rapalini, Augusto E.

2016-10-01

The widespread Sanrafaelic remagnetization reset most of the early Cambrian to mid-Ordovician carbonate platform of the Argentine Precordillera and the calcareous units of the San Rafael Block. We conducted a detailed rock-magnetic study on the Middle-Ordovician limestones of the Ponón Trehué Formation at both limbs of a tight anticline exposed in the San Rafael Block (Mendoza province, central-western Argentina) that are carriers of a syntectonic magnetization of Permian age. We found that the magnetic overprint in the Ponón Trehué Formation is carried by both pyrrhotite and magnetite, with goethite and subordinate haematite likely related to weathering. Hysteresis parameters, frequency dependence of magnetic susceptibility, Cisowski and modified Lowrie-Fuller tests suggest the presence of ultrafine particles of chemical origin. Demagnetization of natural remanent magnetization and of three-axis isothermal remanence confirm pyrrhotite and magnetite as important contributors to the remanence. Both minerals carry the same magnetic syntectonic component suggesting a coeval or nearly coeval remanence acquisition and therefore mineral formation. This and the results of the magnetic fabric analyses indicate an authigenic origin of the magnetic minerals during folding associated with the Sanrafaelic tectonic phase (ca. 280 Ma). Although the chemically active (oxidizing?) fluids expelled from the orogen as it developed in the early Permian is a viable explanation for the Sanrafaelic remagnetization, the role of the nearly coeval magmatism in Precordillera and the San Rafael Block remains to be properly evaluated.

The impact of levothyroxine sodium treatment on oxidative stress in Hashimoto's thyroiditis.

PubMed

Ates, Ihsan; Altay, Mustafa; Yilmaz, Fatma Meric; Topcuoglu, Canan; Yilmaz, Nisbet; Berker, Dilek; Guler, Serdar

2016-06-01

Although several studies reported increased oxidative stress in Hashimoto's thyroiditis (HT), the effect of levothyroxine treatment on oxidative status is not studied extensively. Therefore, we conducted this study to investigate the effects of levothyroxine replacement on oxidative stress in HT. Thirty-six patients recently diagnosed with HT-related hypothyroidism and 36 healthy controls were included in the study. Levothyroxine replacement was started to patients with hypothyroidism, and had been followed-up for 6 months. Mean basal serum total antioxidant status (TAS), total thiol, arylesterase, and paraoxonase 1 (PON1) levels were significantly lower, and serum total oxidant status (TOS) and oxidative stress index (OSI) were significantly higher in the patients with hypothyroid than the controls. In the hypothyroid group serum TAS, total thiol, arylesterase, and PON1 levels increased and serum TOS and OSI levels decreased significantly after levothyroxine treatment. Pretreatment serum TAS, total thiol, PON1, and arylesterase levels were positively correlated with free levothyroxine (fT4) and negatively correlated with thyroid-stimulating hormone (TSH), antithyroid peroxidase (anti-TPO), and antithyroglobulin (anti-TG) levels. Also, pretreatment serum TOS and OSI levels were negatively correlated with fT4 levels and positively correlated with TSH, anti-TPO, and anti-TG. We have also found that the fT4 and anti-TPO levels are independent predictors of the oxidative stress parameters in stepwise multivariable linear regression analysis. This study suggests that levothyroxine replacement decreases oxidant status and increases antioxidant status following the 6 months of levothyroxine replacement in hypothyroidism that develops in accordance with the HT. © 2016 European Society of Endocrinology.

Chirp-aided power fading mitigation for upstream 100 km full-range long reach PON with DBR DML

NASA Astrophysics Data System (ADS)

Zhang, Kuo; He, Hao; Xin, Haiyun; Hu, Weisheng; Liang, Song; Lu, Dan; Zhao, Lingjuan

2018-01-01

The DML is a promising option for cost-sensitive ONUs in optical access networks, but suffers from severe power fading due to dispersion and chirp. In this work, we investigate to mitigate the power fading by optimizing the chirp. Theoretical analysis indicates, a see-saw effect, influenced by the bias, exists between the adiabatic notch-induced fading (A-fading) and the transient notch-induced fading (T-fading). High bias can mitigate T-fading, but causes large A-fading. Low bias can avoid A-fading, but cannot completely mitigate T-fading. For each transmission distance, balance should be achieved to favor transmission. The ∼20 km short distance requires high bias to obtain large adiabatic chirp to counteract the T-fading, while the ∼100 km long distance requires relatively low bias to avoid the A-fading. With this power fading mitigation technique, we conduct upstream transmission experiment of LR-PON. Experiments show that, although signal contamination is inevitable, clear ;1; and ;0; are obtained with this power fading mitigation scheme for any 0 ∼100 km distance with 10 Gb/s OOK signal and DBR DML. The optical power budget penalty induced by 0 ∼100 km fiber is limited within only 2.2 dB, with optimum bias for each distance. More than 10 and 15 dB improvement is achieved when BER is 10-3 and 10-6. A method is also proposed to automatically obtain optimum bias from the ranging procedure of PON protocol.

Social Cognition Psychometric Evaluation: Results of the Final Validation Study.

PubMed

Pinkham, Amy E; Harvey, Philip D; Penn, David L

2018-06-06

Social cognition is increasingly recognized as an important treatment target in schizophrenia; however, the dearth of well-validated measures that are suitable for use in clinical trials remains a significant limitation. The Social Cognition Psychometric Evaluation (SCOPE) study addresses this need by systematically evaluating the psychometric properties of promising measures. In this final phase of SCOPE, eight new or modified tasks were evaluated. Stable outpatients with schizophrenia (n = 218) and healthy controls (n = 154) completed the battery at baseline and 2-4 weeks later across three sites. Tasks included the Bell Lysaker Emotion Recognition Task (BLERT), Penn Emotion Recognition Task (ER-40), Reading the Mind in the Eyes Task (Eyes), The Awareness of Social Inferences Test (TASIT), Hinting Task, Mini Profile of Nonverbal Sensitivity (MiniPONS), Social Attribution Task-Multiple Choice (SAT-MC), and Intentionality Bias Task (IBT). BLERT and ER-40 modifications included response time and confidence ratings. The Eyes task was modified to include definitions of terms and TASIT to include response time. Hinting was scored with more stringent criteria. MiniPONS, SAT-MC, and IBT were new to this phase. Tasks were evaluated on (1) test-retest reliability, (2) utility as a repeated measure, (3) relationship to functional outcome, (4) practicality and tolerability, (5) sensitivity to group differences, and (6) internal consistency. Hinting, BLERT, and ER-40 showed the strongest psychometric properties and are recommended for use in clinical trials. Eyes, TASIT, and IBT showed somewhat weaker psychometric properties and require further study. MiniPONS and SAT-MC showed poorer psychometric properties that suggest caution for their use in clinical trials.

Frequencies of Functional Polymorphisms in Three Pharmacokinetic Genes of Clinical Interest within the Admixed Puerto Rican Population

PubMed Central

Orengo-Mercado, Carmelo; Nieves, Bianca; López, Lizbeth; Vallés-Ortiz, Nabila; Renta, Jessicca Y.; Santiago-Borrero, Pedro J.; Cadilla, Carmen L.; Duconge, Jorge

2013-01-01

Objective This cross-sectional study was aimed at determining the allele frequencies for the CYP2C19*2, CYP2C19*3, CYP2D6*10 and PON1 (rs662) polymorphisms in the Puerto Rican population. The CYP2C19, CYP2D6 and PON1 genes are known to be associated with functional changes in drug metabolism and activation. Individuals carrying the aforementioned polymorphisms are at a higher risk of suffering from drug-induced adverse events and/ or unresponsiveness from a variety of drugs that includes antidepressants, atypical antipsychotics and antiplatelet compounds. Information on the frequency of these polymorphisms is more commonly found on homogeneous populations, but is scarce in highly heterogeneous populations like Hispanics, as in the case of Puerto Ricans. Method Genotyping was carried out in 100 genomic DNA samples from dried blood spots supplied by the Puerto Rican Newborn Screening program using Taqman® Genotyping Assays. Results The Minor Allele Frequencies (MAF) obtained were 9% for CYP2C19*2 and CYP2D6*10, 50% for PON1 (rs662), while the CYP2C19*3 variant was not detected in our study. Furthermore, Hardy Weinberg equilibrium analysis was assessed as well as a comparison between Puerto Rico and other reference populations using a Z-test for proportions. Conclusion The observed allele and genotype frequencies on these relevant pharmacogenes in Puerto Ricans were more closely related to those early reported in two other reference populations of Americans (Mexicans and Colombians). PMID:24040574

Frequencies of Functional Polymorphisms in Three Pharmacokinetic Genes of Clinical Interest within the Admixed Puerto Rican Population.

PubMed

Orengo-Mercado, Carmelo; Nieves, Bianca; López, Lizbeth; Vallés-Ortiz, Nabila; Renta, Jessicca Y; Santiago-Borrero, Pedro J; Cadilla, Carmen L; Duconge, Jorge

2013-03-27

This cross-sectional study was aimed at determining the allele frequencies for the CYP2C19*2, CYP2C19*3, CYP2D6*10 and PON1 (rs662) polymorphisms in the Puerto Rican population. The CYP2C19, CYP2D6 and PON1 genes are known to be associated with functional changes in drug metabolism and activation. Individuals carrying the aforementioned polymorphisms are at a higher risk of suffering from drug-induced adverse events and/ or unresponsiveness from a variety of drugs that includes antidepressants, atypical antipsychotics and antiplatelet compounds. Information on the frequency of these polymorphisms is more commonly found on homogeneous populations, but is scarce in highly heterogeneous populations like Hispanics, as in the case of Puerto Ricans. Genotyping was carried out in 100 genomic DNA samples from dried blood spots supplied by the Puerto Rican Newborn Screening program using Taqman® Genotyping Assays. The Minor Allele Frequencies (MAF) obtained were 9% for CYP2C19*2 and CYP2D6*10, 50% for PON1 (rs662), while the CYP2C19*3 variant was not detected in our study. Furthermore, Hardy Weinberg equilibrium analysis was assessed as well as a comparison between Puerto Rico and other reference populations using a Z-test for proportions. The observed allele and genotype frequencies on these relevant pharmacogenes in Puerto Ricans were more closely related to those early reported in two other reference populations of Americans (Mexicans and Colombians).

Cholinergic stimulation of the pons depresses respiration in decerebrate cats.

PubMed

Kimura, H; Kubin, L; Davies, R O; Pack, A I

1990-12-01

The injection of carbachol into the pontine tegmentum of decerebrate cats evokes a postural motor atonia that has many of the characteristics of the atonia of natural rapid-eye-movement (REM) sleep (Morales et al. J. Neurophysiol. 57: 1118-1129, 1987). We have used the carbachol-injected decerebrate cat to study the changes in respiratory neuronal activity that accompany the atonia. The activities of representative respiratory motor nerves--phrenic, intercostal, and hypoglossal--and that of a motor branch of C4 were recorded in decerebrate, vagotomized, paralyzed, and artificially ventilated cats. After the microinjection of carbachol, there was a profound suppression of activity in all the nerves and a decrease in respiratory rate. This was a consistent stereotyped response in which the magnitude of the suppression of respiratory-related activity was phrenic (to approximately 65% of control) less than inspiratory intercostal (approximately 50%) less than hypoglossal (approximately 10%) less than expiratory intercostal (approximately 5%). The decrease in respiratory rate (to approximately 70% of control) was caused by a prolongation of both inspiratory and expiratory durations. Complete reversal of the carbachol effect was elicited by the microinjection of atropine into the same site as the carbachol injection. This allowed us to produce a second episode of atonia by the injection of carbachol into the contralateral pons. Thus we have demonstrated the existence of neural pathways originating in the cholinoceptive cells of the pons that have the potential to powerfully and differentially depress various respiratory motoneuronal pools and to reduce the respiratory rate. These pathways are likely to be activated along with the atonia of REM sleep.

Summer nitrogenous nutrient transport and its fate in the Taiwan Strait: A coupled physical-biological modeling approach

NASA Astrophysics Data System (ADS)

Wang, Jia; Hong, Huasheng; Jiang, Yuwu; Chai, Fei; Yan, Xiao-Hai

2013-09-01

In order to understand the fate of nutrients in the Taiwan Strait during summer, we built a coupled physical-biological numerical ocean model, which can capture the basic hydrographic and biological features within the strait. The nutrient that we chose to model is dissolved inorganic nitrogen (DIN). The model includes individual reservoirs for nitrate (NO3) and ammonium (NH4). Both the observational evidence and model results show that NO3 in the strait originates primarily from the upwelling subsurface water in the northern South China Sea (SCS) that enters the strait via the eastern and western routes separated by the Taiwan Bank. The coupled physical and biological effects on the NO3 transport at these two routes are highlighted in the study. For the western route, the shallow topography and the coastal upwelling intensify the biological uptake of NO3 in the whole water column. Consequently, the nitrogenous contribution by this route is mainly in form of the particulate organic nitrogen (PON). In contrast, NO3 is transported conservatively below the nitricline at the deep eastern route, contributing the whole NO3 supply in the TWS. The model estimates the fluxes of DIN and PON into the TWS, from the northern SCS, are 1.8 and 4 kmol s-1, respectively. Over half (˜1 kmol s-1) of the DIN is synthesized into PON by the phytoplankton in the strait. Overall, this study estimates the physical and biological effects on the nutrient transport in the TWS during summer.

Deploying Monitoring Trails for Fault Localization in All- Optical Networks and Radio-over-Fiber Passive Optical Networks

NASA Astrophysics Data System (ADS)

Maamoun, Khaled Mohamed

Fault localization is the process of realizing the true source of a failure from a set of collected failure notifications. Isolating failure recovery within the network optical domain is necessary to resolve alarm storm problems. The introduction of the monitoring trail (m-trail) has been proven to deliver better performance by employing monitoring resources in a form of optical trails - a monitoring framework that generalizes all the previously reported counterparts. In this dissertation, the m-trail design is explored and a focus is given to the analysis on using m-trails with established lightpaths to achieve fault localization. This process saves network resources by reducing the number of the m-trails required for fault localization and therefore the number of wavelengths used in the network. A novel approach based on Geographic Midpoint Technique, an adapted version of the Chinese Postman's Problem (CPP) solution and an adapted version of the Traveling Salesman's Problem (TSP) solution algorithms is introduced. The desirable features of network architectures and the enabling of innovative technologies for delivering future millimeter-waveband (mm-WB) Radio-over-Fiber (RoF) systems for wireless services integrated in a Dense Wavelength Division Multiplexing (DWDM) is proposed in this dissertation. For the conceptual illustration, a DWDM RoF system with channel spacing of 12.5 GHz is considered. The mm-WB Radio Frequency (RF) signal is obtained at each Optical Network Unit (ONU) by simultaneously using optical heterodyning photo detection between two optical carriers. The generated RF modulated signal has a frequency of 12.5 GHz. This RoF system is easy, cost-effective, resistant to laser phase noise and also reduces maintenance needs, in principle. A revision of related RoF network proposals and experiments is also included. A number of models for Passive Optical Networks (PON)/ RoF-PON that combine both innovative and existing ideas along with a number of solutions for m-trail design problem of these models are proposed. The comparison between these models uses the expected survivability function which proved that these models are liable to be implemented in the new and existing PON/ RoF-PON systems. This dissertation is followed by recommendation of possible directions for future research in this area.

Point-of-need detection using surface-based biosensors with an examination of protein immobilization and development of magnetic labels

NASA Astrophysics Data System (ADS)

Lim, China Ye-Ling

Over the past decade, our research group has worked on developing surface-based immunoassays to detect disease biomarkers. Our immunoassay platforms use a gold surface coated with an N-hydroxysuccinimide (NHS)-based monolayer and a layer of antibodies to capture a target antigen. Readout is achieved by surface-enhanced Raman scattering (SERS) or giant magnetoresistance (GMR) after labeling of the captured antigen with Raman dye-modified gold nanoparticles or magnetic particles, which are also coated with antibodies. Both of these platforms enable the low-level detection of numerous biomarkers and have the potential for translation into a point-of-need (PON) (i.e., rapid, easy to use, and field deployable) test. As part of an effort to develop a PON test, this dissertation includes investigations of: (1) SERS-based detection of botulinum neurotoxins (BoNTs), (2) protein immobilization procedures, and (3) magnetic microcapsules (MMCs) for use with GMR detection. First, a SERS-based immunoassay for bioterrorism agents, botulinum neurotoxins A (BoNT-A) and B (BoNT-B) with picomolar (or lower) detection limits for BoNT-A and BoNT-B in buffer and serum is described. These results not only demonstrate sufficient detection of these markers at levels important to homeland security and human health monitoring, but also the potential to translate this methodology to a PON test. Next, the reactivity of NHS ester-terminated monolayers, a common approach in protein immobilization chemistry, is investigated to assess the competition of the purported amidization reaction to that of hydrolysis. Results of kinetic studies on hydrolysis and aminolysis under relevant assay conditions show the rate of hydrolysis is 300x faster than that of aminolysis. These results indicate that it is highly unlikely that proteins are covalently linked to the surface and suggest that the protein layer is adsorbed via hydrophobic, hydrogen bonding, and electrostatic interactions. The last section examines the development of an MMC-based label. With marked improvement in both stability and magnetization over commercially-available magnetic nanoparticles, these MMCs show potential for the eventual enhanced function as a label in a GMR-based immunoassay. With these results, this dissertation aims to set the stage for the rational development of assays that will facilitate a paradigm shift towards PON tests.

Prenatal pesticide exposure and PON1 genotype associated with adolescent body fat distribution evaluated by dual X-ray absorptiometry (DXA).

PubMed

Tinggaard, J; Wohlfahrt-Veje, C; Husby, S; Christiansen, L; Skakkebaek, N E; Jensen, T K; Grandjean, P; Main, K M; Andersen, H R

2016-07-01

Many modern pesticides have endocrine disrupting abilities and early-life exposure may affect growth and disease risk later in life. Previously, we reported associations between prenatal pesticide exposure and higher childhood body fat content measured by anthropometry. The associations were affected by child PON1 Q192R genotype. We aimed to study whether prenatal pesticide exposure was still associated with body fat content and distribution in the children at puberty and the potential impact of both maternal and child PON1 Q192R genotype. In this prospective cohort study of 247 children born by occupationally exposed or unexposed women (greenhouse workers and controls) two follow-up examinations (age 10-15 and 11-16 years) including simple anthropometry, skinfold measurements, pubertal staging and blood sampling were performed. Total and regional fat% was determined by dual X-ray absorptiometry (DXA) at age 10-15. Prenatal pesticide exposure was associated with increased total, android, and gynoid fat percentage (DXA) at age 10-15 years after adjustment for sex, socioeconomic status, and puberty (all β = 0.5 standard deviation score (SDS) p < 0.05). Stratified by sex, the associations were significant in girls (total fat: β = 0.7 SDS, android-gynoid ratio: β = 0.1, both p < 0.05), but not in boys. Carrying the R-allele (child or mother, separately, or both) augmented the differences between exposed and unexposed children (total fat: β = 1.0 SDS, β = 0.8 SDS, p < 0.05, respectively, and β = 1.2 SDS, p < 0.01). No exposure-related differences were found if either the child or mother had the QQ wild-type. At age 11-16, exposed children tended to have a higher total fat% estimated by skinfolds than unexposed children (p = 0.06). No significant associations between prenatal exposure and body mass index or waist circumference were found. Prenatal pesticide exposure was associated with higher adolescent body fat content, including android fat deposition, independent of puberty. Girls appeared more susceptible than boys. Furthermore, the association depended on maternal and child PON1 Q192R genotype. © 2016 American Society of Andrology and European Academy of Andrology.

Esterase detoxification of acetylcholinesterase inhibitors by human or rat liver in vitro

EPA Science Inventory

Organophosphate (OP) and N-methylcarbamate pesticides inhibit acetylcholinesterase (AChE), but differences in metabolism and detoxification can influence potency of these pesticides across and within species. Carboxylesterase (CaE) and A-esterase (paraoxonase, PON) are considered...